The Mobilizing Effect of Party System Polarization. Evidence From Europe

• Published date: 01 July 2024
• DOI: http://doi.org/10.1177/00104140231194059
• Author: Fabio Ellger
• Date: 01 July 2024
• Subject Matter: Articles

Article

Comparative Political Studies

2024, Vol. 57(8) 1310–1338

© The Author(s) 2023

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DOI: 10.1177/00104140231194059

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The Mobilizing Effect of

Party System

Polarization. Evidence

From Europe

Fabio Ellger

1



Abstract

Does party system polarization mobilize voters? Polarization is increasingly

shaping democratic competition across Europe. While often perceived to be

negative, polarization can be an effective remedy against voter disengagement.

This paper investigates two distinct, but often conf‌lated mechanisms, which

could explain why polarization leads to mobilization. Spatial polarization of

parties diversif‌ies electoral options at the ballot, while affective polarization

mobilizes based on emotional considerations. This article then shows the link

between polarization and turnout across 22 European countries. The results

are complemented by a difference-in-differences analysis of German local

elections. However, voting results alone do not inform about the mechanism

at play. Survey data is used to show that negative affect appears to be the main

driver of voter participation. Party polarization thus has ambivalent conse-

quences for democracies: It mobilizes the electorate, but its effect is driven by

negative emotions.

Keywords

polarization, voting behavior, voter turnout, representation

1

Transformations of Democracy Unit, WZB Berlin Social Science Center, Berlin, Germany

Corresponding Author:

Fabio Ellger, Transformations of Democracy Unit, WZB Berlin Social Science Center,

Reichpietschufer 50, Berlin 10785, Germany.

Email: fabio.ellger@wzb.eu

Data Availability Statement included at the end of the article

Introduction

What did the general elections of Germany 2017, Spain 2015, and Austria

1995 have in common? At a f‌irst glance, the dynamics around election day

have been quite dissimilar: The German right-wing party “Alternative for

Germany”(AfD) gained representation for the f‌irst time in 2017 and became

the largest faction in opposition. In 2015, Spanish anti-austerity movements

joined forces as the newly formed Podemos party was successfully entering

parliament on a radical left platform. Finally, the established Freedom Party of

Austria FP ¨

Ohad only recently overhauled its prof‌ile in 1995 under its new

eccentric leader: J¨

org Haider abandoned moderate positions in exchange for

populist and nationalist appeals. These changes in European party systems

originated from different actions and dynamics, such as party formations or

leadership change. But all three elections experienced a signif‌icant increase in

turnout as parties were able to mobilize larger shares of the electorate. This

paper argues that there has been a common cause: an increase in polarization

of the party systems.

These examples also reveal that polarization can be volatile in systems of

proportional representation, which are associated with higher degrees of

polarization in the f‌irst place. To test the argument of voter mobilization

through polarization, I conduct a range of cross-sectional and panel data

analyses.

1

First, I show that polarization is associated with higher levels of

turnout in 22 parliamentary democracies across Europe. Second, I make use of

the uneven participation of the newly formed AfD at German local elections

around 2013 to implement a difference-in-differences design. The results

show that the “Alternative for Germany,”as a newly formed right-wing party

boosted participation in localities where it was on the ballot. This empirical

case study nicely complements the initial results. Both analyses suggest that

party polarization and voter turnout are closely linked, but reveal little in-

formation on the mechanism that connects both phenomena. In a third

analysis, I therefore investigate dynamics within cross-country survey data to

disentangle spatial from affective polarization. I contribute to the growing

literature on polarization and voting behavior by operationalizing spatial and

affective polarization as distinct mechanisms. Upon closer analysis, negative

affect appears to be the most relevant predictor of turnout.

Overall, polarization can be considered an effective remedy against po-

litical disengagement. However, increasing voter involvement comes at a

substantial cost: If turnout is driven by negative emotions, polarization can

further undermine the legitimacy of democratic decision-making. In the

concluding discussion, I elaborate on potential implications of these f‌indings

for the study of polarization and turnout in Europe and beyond. Importantly,

this study highlights the affective component of mobilization, which so far

received little attention in comparative research. In part, this is due a lack of

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