Challenging the Mainstream
Sara B Hobolt, London School of Economics and Political Science
Catherine de Vries, University of Essex
Abstract
European democracies are undergoing a transformation. The major parties of the left and the
right that have dominated politics of decades are losing both members and electoral support.
The nature of political competition is also changing. Elections are increasingly fought on new
issues, such immigration, European integration and multiculturalism, that challenge the
dominance of the traditional economic left-right dimension. There are many persuasive accounts
of these developments in European party politics, yet in this paper we focus on a key driver that
deserves further consideration, namely the role of challenger parties. Our argument is simple.
Challenger parties exploit the weakening ties between mainstream parties and voters to their
own advantage with profound consequences for party competition. In this paper, we focus
specifically on how challenger parties use issue entrepreneurial strategies to restructure the
political agenda, in most cases without ever setting foot in government. Analysing data crossnational and cross-temporal expert and survey data from 14 West European democracies, we
show that challenger parties are more likely have mobilize two political issues that are not easily
subsumed in the left-right dimension, namely immigration and European integration, in an
effort to attract voters and gain policy influence.
**This paper is part of a larger book project in which we introduce the concept and measurement of
challenger parties and identify different ways in which they have contributed to the changes we have
witnessed in party and electoral politics in post-war Western Europe.**
Paper to be presented at the EUI workshop “Rejected Europe. Beloved Europe. Cleavage Europe?"
May 2017

The research for this paper was generously supported by the European Research Council (ERC GA 647835,
EUDEMOS).
1
Introduction
European party systems are changing. The major parties of the left and the right that have
dominated politics for decades are losing ground. Some even argue that the “age of party
democracy” has passed (Mair 2013). Indeed, there are many indications that established political
parties are in decline, including falling electoral support and turnout, the rise of voter volatility
and declining party membership and party identification (Dalton and Wattenberg 2000). The
nature of political competition is also changing: the socio-economic cleavages that used to
dominate party competition and party ties are becoming less relevant, and new salient issues
have emerged, such as immigration and European integration (Kriesi et al. 2006; Hooghe and
Marks 2017). Yet, the changes in party systems are not uniform across individual countries in
Western Europe. In some, we find that the mainstream has been able to successfully maintain its
dominance, whereas in others the fragmentation of party politics and the emergence of new
salient issues occurred already some decades ago.
To understand changing West European political landscape, this paper argues that it is
not sufficient to study the decline of mainstream parties and the structural factors that underlie
this decline, we must also examine the role of another type of party, namely challenger parties.
We broadly define challenger parties as those outside the political mainstream party families, i.e.
parties on the left and right political extremes, green parties, regionalist parties and single-issue
parties. We argue that what distinguishes challenger parties from other parties is that they seek
to challenge the mainstream consensus in three ways. First, challenger parties mobilize new
issues, specifically those that are not closely aligned to traditional left-right politics, such as
immigration, European integration and direct democracy. Second, they reject the traditional
politics of compromise and coalition-building that is central to most European governments.
Unlike mainstream office-seeking parties, challenger parties are reluctant to enter coalition
governments, if it involves messy compromises combined with greater accountability. Finally,
the leaders of challenger parties distance themselves from the traditional political class, not only
in terms of policies, but also in style and rhetoric, and present themselves as different from the
political elite. Notable examples of successful challenger parties include Front National in
France, the Freedom Party in the Netherlands, Podemos in Spain, the Five Star Movement in
Italy, and the Danish People’s Party in Denmark. Such parties have transformed the nature of
party competition and have restructured the political agenda, in most cases without ever setting
foot in government.
2
This paper looks firstly at the loosening ties between mainstream parties and the
electorate, examining changes in both electoral support and party membership. Secondly, it
examines one of the main strategies used by challenger parties, namely issue entrepreneurship
(Hobolt and de Vries 2015). Challenger parties are more likely to mobilize issues that have been
largely ignored in party competition and adopt a policy position on the issue that is substantially
different from the mainstream status quo. We test this explicitly by examining the mobilization
of two increasingly salient issues, namely immigration and European integration. Arguably,
immigration and European integration are among the clearest examples of issue competition
over issues that are not easily aligned with the economic left-right dimension within European
multiparty systems (e.g. Kriesi et al 2006, 2008). Both issues tend to split mainstream parties and
their supporters on the left and right (Van der Brug and Van Spanje 2009).
The paper proceeds as follows. The first section briefly summarizes the evidence
showing the clear, but uneven, loosening of ties between mainstream parties and their
electorates in Western Europe over the last decades. Thereafter we focus on one of the main
strategies of challenger parties in seeking to lure voters to their fold, namely issue
entrepreneurship. To test our argument that challenger parties are more likely to be issue
entrepreneurs, we utilize three rich data sources on party and voter attitudes towards
immigration and European integration, namely the Chapel Hill Expert Surveys (CHES),
Eurobarometer surveys, the European Social Survey and the European Election Studies, which
allow us to inspect the dynamics of issue competition across European party systems. Our
findings showing that challenger parties are most likely to act as issue entrepreneurs, even
controlling for party size and ideological position, lend strong support to our argument. We
conclude by discussing the wider implications of successful challenger parties.
The Mainstream is Losing Ground
Political scientists have long argued that political parties are crucial to the functioning of
democracy (Schattschneider 1942; Dalton and Wattenberg 2000). Parties are essential in linking
citizens to government, by producing policy programmes that give voters clear choices in
elections and provide disciplined and cohesive grouping in legislatures and government that can
implement these programmes and be held accountable in subsequent elections. Political parties
3
represent citizens’ preferences by articulating and aggregating particular interests that in turn
leads to party competition on choices of alternative mandates for governing. The political science
literature on West European party systems is firmly rooted in Seymour Martin Lipset and Stein
Rokkan’s (1967) pioneering work on cleavage structures. Lipset and Rokkan’s theory hypotheses
how macro developments, the national revolution, the Reformation, and the Industrial
Revolution, produce enduring structures of conflict that shape political structure, political
organisation, and the substantive character of conflict. Cleavages arose out of social structures,
chiefly, class, religion, and spatial location, which determined political preferences and partisan
allegiances. These cleavages produced the major party families that have dominated West
European politics for decades: the Conservative, Liberal, Christian Democratic and Socialist
party families. Yet, as the underlying societal foundations of the party system have changed, one
implication is that new generations of citizens may not find a place in frozen party system. This
gradual erosion of the cleavage structure was highlighted by Lipset and Rokkan themselves wjo
noted that “decades of structural change and economic growth have made the old, established
alternatives increasingly irrelevant” (Lipset and Rokkan 1967: 54). Indeed, the links between
social structure and political preferences that Lipset and Rokkan identified in 1967 appear much
looser today (Franklin, Mackie and Valen 1992; Dalton and Wattenberg 2000). Traditional models
that conceive stable electorates strongly tied to specific parties through deeply rooted social
divisions (Lazarsfeld et al. 1944, Lipset and Rokkan 1967) are no longer accurate depictions of
party competition characterised by high electoral volatility and new party entries.
There is an extensive literature pointing to the decline of political parties. While parties
continue to play a central role in government as policy-makers, many studies show the growing
public detachment with political parties (see Dalton and Wattenberg 2000 for an overview). Peter
Mair (2005) highlights four pieces of evidence that demonstrate the weakening ties between
parties and voters, namely declining electoral turnout; a rise of voter volatility, falling levels of
party identification and a decline in party membership.
In Mair’s last book, published
posthumously in 2013, he went as far as arguing: “The age of party democracy has passed.
Although the parties themselves remain, they have become so disconnected from the wider
society, and pursue a form of political competition that is so lacking in meaning, that they no
longer seem capable of sustaining democracy in its present form” (2013:1). While his conclusion
that parties can no longer sustain democracy may be disputed, there is considerable evidence
suggesting that parties have become more disengaged from voters. Perhaps one of the clearest
4
indications of this is the steep decline in party membership, as shown in Figure 1. The party
membership data reported in Figure 1 is based on the Members and Activists of Political Parties
(MAPP) project by the MAPP working group.1 The figures clearly show a steep decline in party
membership figures, across Western Europe. The one exception is Spain where there has been an
increase in recent years, mostly due to the establishment of two new national parties Podemos
and Cuidadanos. Most other Western European countries have seen a steep decline in party
membership figures from the 1980s and 1990s onwards.
This group of academics has conducted the most comprehensive data collection on party membership so far in
Europe so far. The data can be accessed via: http://www.projectmapp.eu/databases/.
1
5
Figure 1: Party Membership in Western Europe, 1945-2016
6
Source: MAPP dataset
7
This weakening of ties between parties and voters has also led to increasing electoral volatility at
the individual level, as more voters switch parties between elections (see e.g. Mair 2008), as well
as an overall decline in electoral support for the established mainstream party families. This is
illustrated in Figure 2. The figure displays the vote shares in national parliamentary elections of
both challenger and mainstream parties in the post-war period. The data on vote shares are
based on the Parlgov database (Döring and Manow 2017). We distinguish between mainstream
and challenger party electoral success. A variety of terms have been used to describe and
conceptualize “challenger parties” or “niche parties” (see e.g. Meguid 2008; Adams et al.
2006; Jensen and Spoon 2010; Hino 2012). Regardless of the specific nomenclature, all these
authors focus on parties that defy existing patterns of party competition by rejecting the
traditional patterns of party competition. We adopt a conventional approach to the
operationalization of these parties by classifying parties belonging the traditional
conservative, Christian democratic, liberal and socialist party families as “mainstream”
parties, whereas parties belonging to other party families. Challenger parties thus include
parties from the radical left and radical right party family, as well as green, regionalist and
single-issue parties (see also Adams et al. 2006, Ezrow et al. 2011).2 Our classification of
mainstream and challenger is based on their party family membership that was included in
the Parlgov database and we have cross-validated with other data sources like the Chapel
Hill Expert Survey (CHES) Trendfile (Bakker et al. 2015).
This is a conservative way of operationalizing challenger parties, since it does not allow us to distinguish
between communist parties and new left parties, for example. In order work, we have also used other
operationalization of challenger parties, e.g. participation in government in the post-war period (see van der
Wardt, De Vries and Hobolt 2014) and this operationalization yields essentially the same results.
2
8
Figure 2: Mainstream and Challenger Parties Vote Shares from 1945-2016
Source: Parlgov database (Döring and Manow 2017)
9
Interestingly, the figures of party vote shares show that the timing and the magnitude of vote
decline have been far from uniform across Western Europe. This raises the question of why we
have seen the early decline of electoral support for mainstream parties in some countries, like
Denmark for example, whereas the mainstream parties have been able to hold on much longer in
other countries, like the Netherlands for example, where challenger parties only emerged in the
last decades. A classical explanation would highlight the institutional differences, especially the
electoral system (Cox 1990, 1997). No doubt, it is easier for new parties to gain a foothold in the
system when electoral systems are more proportional. Yet, this is not the entire story. If we
compare the Danish and Dutch patterns for example, we witness quite different trajectories for
challenger parties in countries with quite similar political opportunity structures. The same
seems to be true for more disproportional systems like Greece, Spain and the United Kingdom,
where there is clear variation in the cross-temporal dominance of mainstream parties.
Another explanation for these different country patterns is found in the sociological
approach that conceives of political parties as programmatic organisations that mobilise and are
responsive to ideologically self-selected activists and leaders as well as to voters. According to
this account, political parties have limited flexibility in shaping the political agenda. New parties
are largely the result of demand-driven process in which new issues emerge through citizens’
response to rapidly changing social and economic conditions. The changing class structure due
to the increased political and economic integration in Europe accompanied with higher levels of
migration created winners and losers, which in turn is closely tied to the rise and success of
radical right parties and new left parties (Kriesi et al. 2006, 2008; Oesch 2006, 2008, Oesch and
Rennwald 2010).
While insights from the institutional and sociological approaches are no doubt crucial to
the understanding the changing political landscape in Europe, we adopt a different approach for
explaining the pace and substance of changes to party competition across Europe. We argue that
it is crucial to focus on the supply-side, that is the agency of political parties themselves. Building
on classical approaches from the US context, most notably Schattschneider (1960), we develop an
alternative view that focuses more on parties’ strategic choices (see De Vries and Marks 2012;
Hobolt and De Vries 2015). Clearly, these coicesare influenced by broader societal developments
as outlined in the sociological approach, but also driven by the degree to which political parties
themselves are able to generate and maintain political demand. The strategic approach starts
from the Schattschneiderian assumption that politics is a competitive struggle among political
10
parties about which political issues come to dominate the political agenda (Schattschneider
1960). Parties are not vessels carrying societal divisions, but they actively structure and
determine the content of societal conflict. As a result, the substantive character of political
competition will vary from election to election as new issues or positions are identified and
mobilised by one party or another (Carmines and Stimson 1989; Riker 1982). Political parties
politicise a previously non-salient event, policy issue, or societal conflict and attempt to
encourage public attention over this controversy. Of course, they have to carefully choose which
issue to mobilize or position to take in order to ensure that it resonates with people’s interests.
Nevertheless, within the strategic perspective, an issue is likely to structure the political debate
only when a political party or candidate gives it political expression (Carmines and Stimson,
1989, Riker 1982). Introducing a new issue or position involves risk because it “is capable of
subtracting more voters than it adds” (Stimson et al. 2012: 293). Consequently, a political party
will seek to reduce the number of political issues it addresses to the dimension on which it has a
competitive advantage (De Vries and Hobolt 2012). In this view, new parties emerge not only
because a societal demand for them exists and the electoral system is permissive, but perhaps
more importantly because these parties are able to actively shape and exploit their own demand.
One way in which they reshape the political landscape is by mobilizing new issues.
Issue entrepreneurship of challenger parties
To understand why challenger parties mobilize previously ignored issues, we turn to the theory
of issue entrepreneurship that we have set out in greater detail previously (Hobolt and de Vries
2015). At the heart of this theory is the notion that parties mobilize political issues strategically
to win votes. Following the literature on issue evolution (Carmines and Stimson 1986, 1989,
1993) and issue manipulation (Riker 1982, 1986, 1996), we argue that parties want to associate
themselves with winning issues, and thus if a party finds itself outside the political mainstream
it will attempt to redirect political competition. Issues are likely introduced by parties that
occupy losing positions within the system as they have an incentive to unseat the existing
political equilibrium in order to reap electoral gains. One way in which a party can politicize an
issue is to adopt a polarizing position on that issue. When parties are in perfect agreement on
an issue, it is less likely to become important in political debate (Rabinowitz and MacDonald
1989; Carmines and Stimson 1989). Moreover, parties who find themselves in losing positions
11
on the mainstream dimension will likely try to mobilize issues that do not closely aligned with
the dominant dimension to try to drive a wedge between parties and their supporters, between
different factions within mainstream parties or between coalition partners (see for example Van
de Wardt, De Vries and Hobolt 2014). We have coined the term issue entrepreneurship to denote
the party strategy of active mobilization of a previously ignored and non-contested issue by
adopting a policy position on that issue that is substantially different from the status quo
position of the mainstream (Hobolt and de Vries 2015).
Mobilizing new political issues that are not closely aligned with the dominant
dimension of contestation can be risky for mainstream parties as it may lead to internal division
or imperil relationships with past and prospective coalition partners. In contrast, issue
entrepreneurship involves far less risk for challenger parties which are less likely to participate
in government coalitions, and such parties are therefore more likely to mobilize new issues
compared to their mainstream counterparts in opposition. We thus expect that challenger
parties are more likely to engage in issue entrepreneurial strategies.
As discussed above, we classify challenger parties as those that do not belong to the
traditional party families of the centre-left and the centre-right, but include parties on the
radical left and the right, and green, regionalist and single-issue parties (Adams et al. 2006,
Ezrow et al. 2011). This classification includes the Front National in France, the Party of
Freedom in the Netherlands, Podemos in Spain, and the Five Star Movement in Italy, but also
the Greens in France and the Netherlands or regional parties in Spain and Italy for example.
Although these parties are different from each other in many ways and many books and
scholarly articles have been devoted to studying each party family individually, we argue here
that they also have something in common, namely they challenge the mainstream consensus in
three ways. First, challenger parties mobilize new issues, most likely those that are not closely
aligned to traditional left-right politics, such as immigration, European integration and direct
democracy. Second, they are reluctant towards the traditional politics of compromise and
coalition-building that is central to most European governments. Third, the leaders of
challenger parties distance themselves from the traditional political class, not only in terms of
policies, but also in style and rhetoric, and present themselves as different from the political
elite. In this paper we focus primarily on the first element relating to the mobilization of specific
issues.
To attract electoral support, challenger parties have an incentive to mobilize issues that
have been depoliticized or ignored by the mainstream because they cannot easily be subsumed
12
within the left-right dimension and when it has the potential to split mainstream party
platforms, a so-called “wedge issue” (see Van der Wardt, De Vries and Hobolt 2014). Issue
entrepreneurs look for issues where mainstream parties provide limited attention and political
choice and where they can offer an alternative position that will be attractive to at least a
significant proportion of the electorate. The literature on West European party competition has
identified several issues that constitute wedge issues, European integration and immigration in
particular (see Kriesi et al. 2006; Marks and Wilson 2000; Meguid 2005; Green-Pedersen and
Krogstup 2008; Taggart 1998). These are also the issues we focus on in this paper.
Both the immigration and the European integration issue are in many ways ideal issues
to exploit for parties that are losers on the dominant dimension of contestation. First, these
issues can be seen as an issue that is orthogonal to the dominant dimension of left-right politics
(Hooghe et al. 2002, Hobolt and de Vries 2015).
Some scholars have argued that the
immigration issue represents a core component of a new “cultural” dimension of contestation
that is transforming European party competition from a one-dimensional space – centered on
the role of the state in the economy - to a two-dimensional space (see Kriesi et al. 2006, 2008).
The rise of salience of a second cultural dimension represents a challenge to those parties that
are the traditional winners on the economic left-right dimension, and who may struggle to align
their position on immigration with their stance of left-right issues. For example, parties that
occupy a right-wing pro-trade market-liberal position on economic issues may struggle to
reconcile that with a closed-border anti-immigration and anti-EU stance. Similarly, parties that
identify with a state-interventionist left-wing stance may face a dilemma the interest of working
class supporters fearing competition from low-skilled immigrants from the EU and
cosmopolitan professional supporters who favor a liberal immigration policy and further
European integration. Mainstream parties that have dominated traditional left-right party
competition therefore have incentives to downplay both the immigration and the EU issue. This
presents an opportunity for issue entrepreneurs that can politicize these issues by adopting a
position different from the position of the mainstream, typically a more anti-EU antiimmigration stance.
Data and Methods
In the remainder of this paper, we examine one way in which challenger parties
challenge the mainstream consensus, namely by adopting an issue entrepreneurial
13
strategy and mobilizing wedge issues that are not easily aligned in the dominant
dimension of competition. As argued in the previous section issues relating to
immigration and European integration constitute wedge issues par excellence in
Western Europe. By focusing on these issues, we can utilize a rich data source on
party positioning and salience towards immigration, namely the Chapel Hill Expert
Surveys (CHES). This data source provides us with empirical measures of all our key
theoretical concepts. We present evidence from the 1996 through 2014 rounds of the
CHES data for the European integration issue and the 2006 through 2014 rounds for
the immigration issue as only this subset included all measures that were needed.
Our analysis thus includes data over 200 political parties from 14 West European EU
member states excluding Luxembourg.
In order to test our model of issue entrepreneurship, our first task is to
operationalize and measure the dependent variable, namely issue entrepreneurship
of parties regarding European integration and immigration. As described earlier,
issue entrepreneurship is defined as a strategy by which political parties mobilize
wedge issues (those that have been depoliticized or ignored by the mainstream
because they cannot easily be subsumed within the left-right dimension) and offer an
alternative position to that will be attractive to at least a significant proportion of the
electorate. Our definition of issue entrepreneurship thus combines issue salience – the
importance that a party attaches to the issue – and issue position – relative to the mean
party position. Consequently, we need measures of both party positions on European
integration and immigration and the emphasis that parties place on this issue. For
both position and salience measures, we rely on CHES (Ray 1999; Steenbergen and
Marks 2007; Hooghe et al 2010). CHES is ideal for our purposes since it includes
estimates of party positions on several issue dimensions as well as the salience that
each party attaches to it. Although the dataset covers expert evaluations of national
political parties in a variety of European countries between 1984 and 2014, the
salience of the immigration issue is only asked in recent rounds of the survey. So
when it comes to the immigration issue we rely on data fro the 2006, 2010 and 2014
rounds. Party positions and salience relating to the European integration issue were
asked for all rounds of CHES so we include data from 1984 to 2014.
The CHES data has a very wide geographical coverage in Europe as it covers
parties in all EU member states. Several studies have cross-validated the measures of
14
CHES and found that expert data outperform other data sources, such as the
Comparative Manifesto Project (CMP) data and mass survey data. In their study of
party positioning on European integration, Marks et al (2007) find that experts,
manifestos and voter and candidate surveys provide convergent measures of EU
party positions, but that expert data (CHES) is the most valid among those sources. In
a similar cross-validation exercise of different EU salience measures, Netjes and
Binnema (2007) also conclude that expert surveys outperform the other salience
measures in terms of explanatory power. So, while the CHES data contain a shorter
time-series than the CMP data, they provide high-quality cross-national data on both
party positions and salience on a variety of issues.
We capture issue entrepreneurship as a combination of salience and position.
Specifically, we multiply a party’s immigration or European integration salience
(immigration/EU issue salience) score with their distance to the mean position of all
other parties in the system on the immigration or European integration issue
respectively (immigration/EU issue distance). Immigration and EU issue salience for
each party is measured in CHES by asking experts to evaluate ‘the relative importance of
the issue in the party’s public stance’ ranging from the issue is of ‘no importance, never
mentioned by the party’ to the issue is ‘the most important issue for the party’. The
scales differ between years, but we standardize on to range between party’s 1) ‘not
important’ to 10) ‘most important’.3 Party positions on the immigration issue are
operationalized by using an expert question asking experts ‘to consider where political
parties stood on immigration policy in [COUNTRY] in [YEAR]’ on a 10-point scale,
where 0 is ‘fully opposed to a restrictive policy on immigration’ and 10 is ‘fully in favour
of a restrictive policy on immigration’. Party positions on the European integration
dimension are operationalized by using an expert question about the ‘overall orientation
of the party leadership towards European integration’ on a 7-point scale, where 1 is
‘strongly opposed’ and 7 is ‘strongly in favor’. Immigration and EU issue distance are
measured by calculating the absolute distance between the mean immigration/EU
position of all parties in a given country and the immigration or EU position of each
individual party. These distance variables are constructed in such a way that positive
Note that in the 2014 CHES round the immigration salience was based on the question asking experts to rate the
three most important issues for a party. Answers including immigration, ethnic minorities or multiculturalism
are coded as 10, while others as 1.
3
15
values indicate that a party is more anti-immigrant or Eurosceptic than the mean
party position and negative values indicate that a party is more pro-European than
the mean party position. This operationalization reflects a move away from a more
pro-EU and pro-immigration mainstream consensus. By combining the issue salience
and distance measures, our issue entrepreneurship measures for both immigration
and the EU capture the extent to which a party attaches importance to the
immigration or EU issue and adopts a different (and more sceptical) position than the
mean party position.4
To examine if challenger parties are more likely to become issue entrepreneurs
we rely on the challenger party operationalization presented in the previous sections.
Specifically, we define parties as those that do not belong to the traditional party
families of the centre-left and the centre-right. Challenger parties thus include parties
from the radical left and right party family, as well as green, regionalist and singleissue parties (see also Adams et al. 2006, Ezrow et al. 2011). We classified mainstream
and challenger parties based on their party family membership that was included in
the Parlgov database, but cross-validated with the coding included in the CHES
Trendfile (Bakker et al. 2015). The variable challenger party takes on value of 1 when
a party belongs to the radical left and right, green, regionalist or single-issue party
family, and 0 when a party belongs to the Christian Democratic, Social
Democratic/Socialist, Liberal or Conservative party family.
We also aim to examine if issue entrepreneurship constitutes a winning
strategy. We do so by exploring if issue entrepreneurship on immigration or the EU is
more extensive for parties that hold positions that are close to the median voter
position on these issues. We expect issue entrepreneurship to be more pronounced
for parties that are closer to the mean voter on immigration or the EU. The mean
voter positions on immigration in each country and year are measured by relying on
European Social Survey (ESS) data from 2006 and 2010 European Election Survey
(EES) from 2014. The latter survey included an identical question on immigration
policy as was used for party experts in CHES. Specifically, respondents were asked if
4
To capture a “new” position on the issue of European integration and immigration, this
asymmetric measure is justified in the case of the issue of European integration and immigration,
since the literature has shown that the consensus position in West European party systems is a
pro-European and pro-immigration position (e.g. De Vries and Edwards 2009; Kriesi et al. 2008).
16
they were ‘fully opposed to a restrictive policy on immigration’ or ‘fully in favour of a
restrictive policy on immigration’ by placing themselves on a scale from 1 ‘fully in
favour’ to 10 ‘fully opposed’. In the case of the 2006 and 2010 we rely on the ESS
question asking respondents whether to allow many or few immigrants “of a
different race or ethnic group from most [country] people”. The mean voter position
on immigration was obtained by taking the mean value on this scale for all
respondents in a country. To measure the mean voter position on the EU in each
country and year, we use Eurobarometer (EB) surveys. In these surveys
approximately 2000 respondents in each country and in each year were asked the
following question: “Generally speaking, do you think that your country’s
membership of the European Community/ European Union is a good thing, a bad
thing or neither good nor bad?” We use the mean score of this 3-point scale to
construct the mean voter EU position. For party positions of the immigration and EU
issues we rely on the CHES data described above. We create a distance variable for
each party by subtracting the party position on immigration or the EU from the mean
voter position on the same issue.
Our models also include control variables. Specifically, we control for party size
which is measured as the percentage of votes obtained in the latest parliamentary
elections, since it may be argued that larger parties are less likely to become issue
entrepreneurs. Moreover, we include a variable capturing the distance to the mean
party on the left-right dimension as a control. This is to rule out that our explanation
of challenger parties is not simply function on ideological extremity on the left-right
dimension. We use CHES responses to the question on parties left-right stance on
economic issues in a given year, where 0 denotes the extreme left and 10 the extreme
right. In order to capture the distance between the mean party position and the
position of a single party on the left-right dimension, we subtracted a party’s leftright position from the mean left-right position of all parties in the system and use the
absolute distance. The descriptive statistics of all variables can be found in Tables 1.A
and 1.B.
17
Table 1.A: Overview of Descriptive Statistics, Immigration Issue
Mean
SD
N
Immigration Issue
Entrepreneurship
21.36
24.68 379
Challenger Party
0.37
0.48
383
Immigration Voter
Distance
4.00
2.55
379
Distance to mean
party (LR)
2.04
1.22
383
Party Size
11.20
12.60 365
Table 1.B: Overview of Descriptive Statistics, EU Issue
Mean
SD
N
EU Issue
Entrepreneurship
24.65
7.00
1145
Challenger Party
0.48
0.50
1164
EU Voter Distance
0.93
0.45
856
Distance to mean
party (LR)
2.11
1.37
961
Party Size
11.20
12.60 1144
We now turn to the statistical estimation of our models. Our unit of observation
is the party. Due to the natural hierarchies in the data, where parties are nested in
countries, we employ a hierarchical (or multilevel) linear model (HLM). Snijders
(2011) suggests that using a HLM technique allows for a single model that
incorporates the different levels of data without assuming a single level of analysis
and for the modelling of random intercepts at the three levels of analysis, the party,
country- and year-level. While the intercept in traditional linear regression represents
the value taken by the dependent variable when all explanatory variables are held at
zero, the random intercepts that are estimated in a HLM regression indicate that for
18
any given party in any given country and any given year, there are different baseline
propensities that modify this traditional observation-level intercept. This allows us to
account for the fact that parties within a country and year may be more likely to share
common characteristics (and errors) compared to parties in other countries and years.
Overall, HLM regression models facilitate the exploration of the generalizability of
findings across different contexts. As a robustness check, we also estimated an
ordinary linear squares (OLS) regression model with country and year fixed effects.
The results that we present in the next section suggest that this yields virtually
identical results compared to using a HLM regression model. The next section
discusses our empirical results.
Empirical Results
We now go on to examine if our expectation that challenger parties are more likely to engage
in issue entrepreneurship is borne out by the data. To test this, we examine issue
entrepreneurship on the immigration and European integration issue. For both issues, we
present the results based on two sets of analyses. In the first analysis, we aim to explain a
party’s level of issue entrepreneurship based on a party’s type, challenger or mainstream,
whilst controlling for party size and left/right extremity by using a hierarchical linear model.
In the second analysis, we use the same variables to explain issue entrepreneurship but
employ an OLS regression model with county and year fixed effects. We begin by discussing
the results for issue entrepreneurship on immigration, presented in Table 2.
Table 2: Explaining Issue Entrepreneurship on Immigration Issue
19
Model 1: Hierarchical
Model
Coeff.
SE
Model 2: Fixed
Effects Model
Coeff.
SE
Intercept
7.62
3.40
**
-15.46
4.32
Party size
0.42
0.10
***
0.40
0.10
Distance to mean party
(LR)
3.53
0.99
3.56
0.97
8.29
2.75
8.07
2.72
***
***
***
Party Type
Challenger Party
Fixed Effects (country &
year)
***
no
***
yes
Fit statistics
3201.726 (BIC)
0.47 (adj. R2)
N (observations, groups)
355, 42
355
Notes: Table entries are regression coefficients and standard errors. The dependent variable is a
party’s level of issue entrepreneurship on the immigration issue. Model 1 reports results of a
hierarchical linear regression model. Model 2 reports the results of an ordinary least regression
model with country and year dummies (not shown due to space limitations).
*** significant at p ≤ 0.01; ** significant at p ≤ 0.05.
Table 2 suggests that challenger parties are significantly more likely to become issue
entrepreneurs even when we control for their overall size as well as left-right extremity. The
coefficient for challenger parties is positive and statistically significant, suggesting that issue
entrepreneurship is more extensive among challenger parties compared to their mainstream
counterparts. Moreover, Model 2 in Table 2 suggests that these results are robust when we
employ a different estimation method, namely an OLS regression with country and year fixed
effects. What is the size of these effects? Figure 3 presents the predicted levels of issue
entrepreneurship on immigration, represented by the dots, as well the uncertainty around
these estimates, the lines that represent the 95 % confidence intervals, for mainstream and
challenger parties respectively. These predicted levels are calculated based on the regression
coefficients in the fixed effects model presented in Model 2 in Table 2. While the predicted
20
level of issue entrepreneurship on immigration is on average roughly 19 points on a scale
ranging from 0 to 100 for mainstream parties, it is with roughly 28 points on average for
challenger parties. This 9-point difference in issue entrepreneurship constitutes almost a onetenth increase on the issue entrepreneurship scale. This suggests that the effect of challenger
parties is both statically and substantively interesting. The findings presented in Table 2
provide first empirical support for the idea that issue entrepreneurship is more pronounced
among challenger parties that hold losing positions on the dominant dimension of
competition.
Figure 3: Predicted Levels of Immigration Issue Entrepreneurship of Mainstream
and Challenger Parties
Source: The dots represent predicted levels of the dependent variable (issue entrepreneurship on the
immigration issue) for different party types (mainstream versus challenger parties) accompanied by
95 % confidence intervals. These post estimation results are based on the results presented in Model
2 Table 2.
In next step, we examine issue entrepreneurship regarding the EU issue. Like in the
case of the immigration issue, Table 3 presents the results of two analyses. Model 1
where we regressed party’s issue entrepreneurship on party type whilst controlling
for party size and left-right extremity using a hierarchical linear model, and Model 2
in which we use an OLS regression with country and year fixed effects. The results
21
presented in Table 3 suggest that challenger parties are also more likely to act as issue
entrepreneurs when it comes to European integration. The coefficients for the
challenger party dummy are positive and statistically significant both in Models 1
and 2.
Table 3: Explaining Issue Entrepreneurship on EU Issue
Model 1: Hierarchical
Model
Coeff.
SE
Model 2: Fixed
Effects Model
Coeff.
SE
Intercept
21.06
0.44
**
20.95
4.61
***
Party size
-0.04
0.01
***
-0.04
0.02
**
Distance to mean party
(LR)
0.75
0.11
0.82
0.12
4.95
0.39
5.28
0.40
***
***
Party Type
Challenger Party
Fixed Effects (country &
year)
***
no
***
yes
Fit statistics
5586.728 (BIC)
0.32 (adj. R2)
N (observations, groups)
946, 110
946
Notes: Table entries are regression coefficients and standard errors. The dependent variable is a
party’s level of issue entrepreneurship on the immigration issue. Model 1 reports results of a
hierarchical linear regression model. Model 2 reports the results of an ordinary least regression
model with country and year dummies (not shown due to space limitations).
*** significant at p ≤ 0.01; ** significant at p ≤ 0.05.
Figure 4 allows us to inspect the size of this effect. The figure, like Figure 3 before,
plots the predicted level of issue entrepreneurship on the EU for mainstream and
challenger parties respectively and 95 % confidence intervals for these predictions.
While mainstream parties display an average level of issue entrepreneurship that is
22 points on a scale ranging from 0 to 65 overall, challenger parties on average are
predicted to have an issue entrepreneurship level on the EU issue of just below 28.
An increase of 6 points on a 66-points issue entrepreneurship scale is close to a one-
22
tenth difference between challenger parties and mainstream parties. This difference
based on party type is thus both statistically and substantively significant.
Figure 4: Predicted Level of EU Issue Entrepreneurship of Mainstream and
Challenger Parties
Source: The dots represent predicted levels of the dependent variable (issue entrepreneurship on the
EU issue) for different party types (mainstream versus challenger parties) accompanied by 95 %
confidence intervals. These post estimation results are based on the results presented in Model 2 in
Table 3.
In a final step, we examine whether mobilizing the immigration and EU issue can be
perceived as a potentially winning strategy. Specifically, we expect that issue
entrepreneurship should be more extensive for those parties who hold immigration or EU
positions that are closer to the mean voter position. Tables 4 and 5 provide this information
for the immigration and EU issue respectively.
23
Table 4: Immigration as a Winning Issue
Model 1: Hierarchical
Model
Coeff.
SE
Intercept
-10.92
1.74
Party size
-0.02
0.05
Distance to mean party
(LR)
1.33
0.48
-7.69
0.24
**
***
Model 2: Fixed
Effects Model
Coeff.
SE
-10.94
2.61
-0.01
0.05
1.33
0.48
-7.17
0.25
**
***
Winning Issue
Immigration voter
distance
Fixed Effects (country &
year)
***
no
***
yes
Fit statistics
2726.411 (BIC)
0.84 (adj. R2)
N (observations, groups)
355, 42
355
Notes: Table entries are regression coefficients and standard errors. The dependent variable is a
party’s level of issue entrepreneurship on the immigration issue. Model 1 reports results of a
hierarchical linear regression model. Model 2 reports the results of an ordinary least regression
model with country and year dummies (not shown due to space limitations).
*** significant at p ≤ 0.01; ** significant at p ≤ 0.05.
We expect parties to mobilize cross-cutting issues like immigration and European
integration when they are closer to the mean voter on these issues. In line with our
expectation, we find that parties are more likely to mobilize the immigration issue when the
distance between their position on this issue and that of the mean voter decreases. Both
Models 1 and 2 in Tables 3 and 4 show that the coefficients for immigration and EU voter
distance on issue entrepreneurship is negative and statistically significant. This suggests that
parties indeed care about attracting new voters when they embark on an issue
entrepreneurship strategy. When it comes to the immigration issue, when the distance
between a party’s and the mean voter position on the issue increases by one unit, i.e. a party
24
moves away from the voter position, issue entrepreneurship decreases by over 7 points based
on both the hierarchical linear and fixed effects models respectively. In the case of the EU
issue, one unit increase in distance to the mean voter, decreases issue entrepreneurship by
5.25 or 4.62 points based on hierarchical and fixed effects models respectively. These results
are both statistically and substantially significant.
Table 5: The EU as a Winning Issue
Model 1: Hierarchical
Model
Coeff.
SE
Model 2: Fixed
Effects Model
Coeff.
SE
Intercept
28.71
0.62
***
27.66
0.81
***
Party size
-0.12
0.02
***
-0.14
0.01
***
Distance to mean party
(LR)
1.15
0.15
1.20
0.12
-5.25
0.43
-4.62
0.37
**
***
Winning Issue
EU voter distance
Fixed Effects (country &
year)
***
no
***
yes
Fit statistics
3320.88 (BIC)
0.34 (adj. R2)
N (observations, groups)
846, 66
846
Notes: Table entries are regression coefficients and standard errors. The dependent variable is a
party’s level of issue entrepreneurship on the immigration issue. Model 1 reports results of a
hierarchical linear regression model. Model 2 reports the results of an ordinary least regression
model with country and year dummies (not shown due to space limitations).
*** significant at p ≤ 0.01; ** significant at p ≤ 0.05.
Concluding Remarks
The Eurozone and refugee crisis have proven to be real stress-tests for European
democracies. While democratic political institutions are resilient, we cannot be sanguine
about their ability to cope with current and future challenges. One reason for this is that
25
established parties of the centre left and right need to guarantee representation and
accountability in the face of dramatic social and economic transformation at a time in which
they are rapidly losing ground electorally. In parallel to the decline of established political
parties, we are witnessing another trend, namely the rise of challenger parties. Challenger
parties highlight issues such as European integration and immigration that have been
largely ignored by the mainstream and hence may foster new linkages with voters that feel
left behind by mainstream parties. While the linkages between established parties and
citizens are weakening, partly because people are much less rooted in traditional civil
society organisations such as unions, churches and the local community, challenger parties
across Western Europe give a clear voice to the discontent with the political establishment.
This study argues that in order to understand the recent transformation of West European
democracies, it is not sufficient to study the decline of mainstream parties and structural
changes underlying their decline. Rather what is missing from many accounts to date is a
comprehensive understanding of their competitors: challenger parties.
This study presents a first step in attempting to explain which parties are challengers
and which strategies have allowed them to successfully reshape electoral and party politics.
We suggest that challenger parties are those parties that challenge the mainstream
consensus. They challenge the mainstream in three distinct ways. First, they mobilize issues
that are ignored by the mainstream, at least in part because they not closely align with
traditional left-right politics, such as immigration and European integration. Second, they
are reluctant to engage in the traditional politics of compromise and coalition-building that
is central to most European governments. Finally, the leaders of challenger parties distance
themselves from the traditional political class, not only in terms of the issues they mobilize,
but also in style and rhetoric, and present themselves as different from the political elite.
This study examined the first strategy of challenger parties, namely the mobilization of the
immigration and EU issues. These issues are likely introduced by parties that occupy losing
positions within the system as they have an incentive to unseat the existing political
equilibrium in order to reap electoral gains. Both immigration and European integration are
among the most salient topics in electoral politics in European and constitute a major
touchstone of dissent in European party systems. Moreover, we show that the mobilization
of divisive issues like immigration and European integration is more pronounced among
26
parties that hold positions closer to the median voter. In next steps of our book project, we
aim to examine the two other strategies of challenger parties. Specifically. the extent to
which they present themselves as different than the mainstream not only due to the issues
they mobilize, but also based on their style and rhetoric more generally as well as their
rejection of the politics of compromise.
Our findings that challenger parties successfully employ issue entrepreneurship
strategies on immigration and European integration have important implications for our
understanding of the mobilization of these issues specifically and patterns of party
competition more generally. Existing work explaining the mobilization of immigration and
European integration in European party systems has focused very much on the importance
of structural changes in society that led to the expansion of vote shares of particular party
families, most notably the radical right. Although we do not take issue with the fact that
these factors are important, we suggest they are not the entire story. The decline of
mainstream parties and the mobilization of immigration and European integration have
not been uniform across and within countries. We suggest that an important factor has
been somewhat overlooked, namely, the strategic activities of parties. By redirecting our
focus from demand-led towards supply-led factors, we are able to explain which parties are
more likely to mobilize anti-immigration and anti-EU stances that challenge the
mainstream status quo, under which conditions this mobilization is most likely successful,
and with the same model identify the parties that steer clear of the mobilization of
immigration and European integration. Our results also inform our understanding of party
competition more broadly. They suggest that the issue basis of party competition is never a
stable equilibrium, rather it is constantly under siege of parties who in Riker’s terms want
to “beat the current winner”. Much of scholarly work on political change in European
views the structure of party competition as more or less exogenously fixed by underlying
changes in the structure of society, we take issue with this view. The electoral change we
are witnessing in Western Europe today, where mainstream parties are increasingly under
attack and see their vote shares diminishing, is not only a reflection of broad changes in
society, like the decline of the working class or religious constituencies or a rise in
globalization, but also the result of the activities of political entrepreneurs who skillfully
exploit these changes for their own gains. Especially the mobilization of cross-cutting issues
27
have become the backbone of the parties that successfully challenge mainstream party
dominance in Europe.
Our results also give rise to questions that should be addressed in future research.
How do mainstream parties respond to the strategies of issue entrepreneurs? What
happens to the original issue entrepreneurs when issues, such as immigration or European
integration, are adopted by the mainstream? Which voters are most likely to desert
mainstream parties in support of challengers based on issues like immigration and
European integration? How stable are the linkages between challenger parties and these
voters? And finally, what are the consequences of the rise of challenger parties for
government and political stability in Western Europe? We hope to address at least some of
them in a book manuscript that we are currently preparing.
28
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