How Populist Parties enter in competition: A Comparative Analysis of 25 European Countries

This article investigates the systemic determinants behind the emergence of different types of populist parties – radical versus valence – across 25 European countries from 2000 to 2024. Linking theories of populism, party system institutionalization, and political competition, this article tests whether structural features such as polarization, fragmentation, and systemic stability influence the type of populism that dominates in national party systems. Drawing on a dataset of 289 populist parties, the study employs a firth logistic regression model to test the theoretical frameworks. Contrary to conventional assumptions that associate radical populism with systemic crisis and instability, the findings reveal that radical populist parties are more likely to emerge and persist in stable and institutionalized party system. Moreover, this study shows how fragmentation and polarization also appear to contribute to radical populism predominance. By contrast, Valence populist parties are more prevalent in unstable system, particularly in Eastern Europe, where in general there is a higher number of populist parties. This suggests that there is a historical legacy hypothesis that links the type of populism and the post-communist country. In conclusion, this article challenges the narrative that populism is a product of political breakdown. Instead, it reveals how institutionalized systems may create fertile ground for anti-establishment challenges.