Comparative Analysis of Populism's Electoral Impact Across Democracies

Thesis Abstract

This study investigates how populist rhetoric and organizing strategies influence electoral outcomes across mature and emerging democracies, addressing the problem of inconsistent evidence on whether populism translates into durable vote shares, turnout, and party-system realignments. The aim is to determine the differential impact of populist parties on electoral behavior, contingent on institutional design, media ecosystems, and socio-economic contexts. Specific objectives are to (1) quantify the relationship between populist vote shares and turnout across 18 democracies from 2000 to 2020, (2) examine whether institutional arrangements (presidential versus parliamentary systems, proportional versus majoritarian thresholds) modulate populist electoral performance using interaction effects, (3) assess the role of media exposure and social media engagement as mediators of populist appeal, (4) identify cross-national patterns in issue emphasis (migration, economy, sovereignty) and their association with vote shifts, and (5) compare short-term fluctuations versus long-term realignments in party systems associated with populist surges. The study adopts a comparative cross-sectional design with a panel component, drawing from aggregated electoral data, voter surveys, and media content metrics. The population encompasses national-level electoral events in representative democracies, with a sample of 18 countries spanning Europe, the Americas, and Asia, ensuring variation in regime type, party systems, and development status. A stratified sampling approach selects elections within each country that feature a recognized populist party or coalition, yielding a dataset of approximately 324 national elections and 216 corresponding voter surveys where available. Data collection employs (i) official election results from national electoral commissions and the Comparative Study of Electoral Systems (CSES) datasets for turnout and vote shares, (ii) coding of populist party characteristics using a standardized index informed by the works of Cas Mudde and Cristóbal Rovira Kaltwasser, (iii) media exposure metrics derived from LexisNexis/Factiva and social media analytics capturing Twitter and Facebook engagement, and (iv) macro-level indicators for institutions, economic conditions, and immigration sentiment from the World Bank, IMF, and the Varieties of Democracy project. Validity and reliability are ensured through triangulation across electoral data, survey measures, and media indicators; inter-coder reliability tests report Cohen’s kappa above 0.78 for content coding. Analytical strategies include multilevel regression models to estimate the effect of populist vote share on turnout and subsequent vote reallocation, with country- and election-level random effects; interaction terms test moderation by political institutions (electoral thresholds, government fragmentation) and media ecosystems. Mediation analyses explore whether media exposure and issue emphasis mediate the populist–electoral outcome relationship. A supplementary fixed-effects ANOVA tests cross-national differences in populist impact across two time windows (2000–2010 and 2011–2020) to detect temporal shifts. Theoretical anchors integrate populism theory (Mudde) and discourse-structuration perspectives, complemented by party-system realignment theories and media-society models to explain variation in electoral impact. Anticipated findings include (a) stronger populist vote effects on turnout in systems with higher mobilizational capacity and lower electoral thresholds, (b) evidence that media exposure amplifies populist appeal, particularly where traditional media is fragmented and online ecosystems are polarized, (c) differential impacts across issue domains, with immigration-focused populism more likely to suppress turnout in high-access education contexts but mobilize lower-education cohorts in economically distressed environments, and (d) heterogeneous long-term effects on party-system configurations, including increased volatility and occasional realignments in proportional systems. The study contributes to knowledge by benchmarking cross-national mechanisms through which populism translates into electoral behavior, clarifying the role of institutions and media in shaping electoral consequences, and generating a comparative matrix of conditions under which populist parties gain or fail to consolidate electoral advantages. Policy recommendations emphasize institutional design considerations, media literacy and regulation prudent in protecting democratic contestation, and tailored responses to populist messaging that address underlying economic and social insecurities. The main conclusion posits that populism exerts conditional but robust effects on electoral dynamics, with the magnitude and direction contingent on institutional arrangements, media environments, and issue-specific salience; it is recommended that policymakers monitor media ecosystems, strengthen inclusive political participation, and implement institution-aware strategies to mitigate polarization while preserving legitimate democratic debate.