Electoral Nationalization of the Political Parties in Spain.

This study is focused on the nationalization of political parties in Spain understood as the homogeneity of parties' electoral support across constituencies in a national election. The first part of the paper describes the evolution of nationalization from 1977 to the present and shows how the Spanish party system is increasingly nationalized despite the differences across parties. The second part seeks to explain party nationalization determinants. The analysis indicates that the votes received at national level increases party nationalization. The age of the party enhances national parties' nationalization while in subnational parties this variable has a negative effect, pointing to a trade-off between the two groups. Finally, the ideological distance in the left-right axis reduces national parties' homogeneity across districts while founding elections have no effect. [ABSTRACT FROM AUTHOR]