Party system nationalization and local electoral competition: evidence from the 2025 Croatian local elections

This article examines the 2025 Croatian local elections through the lens of party system nationalization and its implications for local electoral competition. Building on scholarship on local democracy, party system nationalization, and post-communist political development, the article explores whether the increasing territorial penetration of national parties has reduced the diversity of local political arenas in Croatia. Methodologically, the study combines institutional analysis with electoral data and applies the Laakso–Taagepera index to measure the effective number of electoral parties across a set of major and mid-sized Croatian cities. The findings suggest that Croatia displays a high degree of party system nationalization, particularly through the organizational reach and territorial dominance of the Croatian Democratic Union (HDZ), but not a uniformly closed local political arena. Instead, the analysis reveals significant territorial variation: larger urban centres tend to exhibit more fragmented and pluralized electoral competition, while smaller and medium-sized local units show more concentrated patterns of competition. The article argues that Croatia’s 2025 local elections illustrate a dual dynamic in which nationalized party competition coexists with uneven forms of local electoral pluralism. These findings contribute to broader debates on the relationship between party system nationalization and the quality of subnational democracy in post-communist Europe.