From rhetoric to responsibility: how government participation reshapes populist euroscepticism

This study examines the strategic repositioning of populist parties on European integration when transitioning from opposition to government. While populist parties frequently employ Eurosceptic rhetoric to mobilize voters and challenge mainstream elites (Taggart 2017), their entry into government confronts them with institutional constraints and coalition pressures that may incentivize strategic adaptation (Wolinetz and Zaslove 2018). We test two competing hypotheses regarding this transformation. The depoliticization hypothesis posits that populist parties reduce the salience of European issues once in power, shifting attention away from EU-related topics to avoid policy contradictions and maintain coalition stability. The moderation hypothesis suggests that governmental responsibility leads populist parties to soften their Eurosceptic positions, adopting more pragmatic stances toward European integration. Our analysis introduces a critical second dimension by distinguishing between established and newly emerged populist parties. We hypothesize that newer populist formations remain more resistant to positional shifts despite institutional integration, as their political survival depends on maintaining anti-establishment credibility and exploiting European integration as a wedge issue to differentiate themselves from competitors (de Vries & Hobolt 2020). Conversely, established populist parties may demonstrate greater flexibility, having already consolidated voter bases and organizational structures that provide insulation from immediate electoral pressures. Our empirical strategy combines quantitative and qualitative approaches to capture both broad patterns and contextual nuances. We utilize the Chapel Hill Expert Survey (CHES) dataset spanning 1999-2024, which provides systematic measurements of party positions on European integration across multiple dimensions and countries over time. This longitudinal data allows us to track positional shifts as parties move between opposition and government. To enhance our understanding of populist party characteristics and their government participation patterns, we complement CHES with the POPPA dataset, which offers detailed information on populist parties' ideological and programmatic profiles. Finally, we employ in-depth case studies of selected populist parties that have transitioned into government, to illuminate the mechanisms underlying positional changes or stability. This mixed-methods design enables us to identify general patterns while understanding the specific political dynamics that drive strategic adaptation or resistance. The research contributes to broader debates about how institutional contexts shape populist party strategies, whether the logic of political responsibility ultimately constrains anti-European discourse or merely displaces it strategically, and how party newness and ideology condition responses to governmental responsibility.