In this article, we examine party positions on sovereignty issues in European countries based on an analysis of party supply. First, we develop an index of sovereignism reflecting the multidimensional articulation and differentiated emphasis put by parties on sovereignist issues. By applying the index to Chapel Hill Expert Survey (CHES) data, the analysis maps all EU member states. Second, we integrate in the analysis party- and country-level data (including the orientations of domestic public opinion). Through multivariate regression analysis we show how party ideology, contextual factors and public mood favoured the spread of party-based sovereignism in European countries.

This article has the purpose to assess if and how party system nationalization affects individual voting behaviour. Previous studies on party system nationalization have focused on systemic processes, exclusively dealing with aggregate data. The authors address this topic from a new empirical perspective, arguing that party system nationalization could act as a context dimension interacting with the vote choice function. How does this specific context dimension moderate the explanatory power of individual-level characteristics? On which determinants of vote choice does party system nationalization have a greater impact? To answer these questions, the authors focus on 23 European countries through the use of the 2009 European Election Study. The empirical analysis shows that in nationalized contexts the impact of the left-right dimension on party support is higher than in territorialized contexts, whereas that of class as well as of culture-related variables is lower. The authors also discuss the implications of these findings.