Electoral Nationalization of the Political Parties in Spain

Abstract

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 fi rst 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.