Whither Nationalization? The Impact of Regional Electoral Democracy on National Party Systems in Western Europe

This paper examines the overlooked impact of regional electoral democracy on party system nationalization in Western Europe. Despite decentralization and the proliferation of regional representative institutions, statewide party systems are portrayed as nationalized. I argue that this paradox reflects methodological nationalism, which obscures territorial dynamics by privileging the nation-state as the unit of analysis. Incorporating regional elections reveals an increasing divergence between regional and national votes. To account for this divergence, I develop a framework of four territorial effects that links the location of causal triggers to the territorial manifestation of outcomes. The framework shows how permissive regional electoral systems and the presidentialization of regional executives strengthen regional and new parties, enabling them to use regional arenas as steppingstones into national politics. By shifting from a national to a regional frame, this paper advances theory on multilevel democracy and provides guidance for overcoming methodological nationalism in electoral research and beyond.