Political scientists have generally viewed politics as two-dimensional, with an economic dimension and a social dimension. However, politics is more complex in situations of regionalism. Decentralization of power to regions with strong identities and the presence of regional parties in such contexts may create an additional political cleavage, a regional cleavage over center-periphery relations. This study seeks to determine whether regions which have benefitted from a significant degree of decentralization and/or have strong regional parties have a regional dimension underlying citizens' perceptions of political parties and actors. It also seeks to determine whether this regional dimension replaces or alternatively complements the conventional dimensions. It performs multidimensional scaling analyses on ratings of parties and candidates in surveys conducted at the national and regional levels in five countries, Canada, France, Germany, Spain, and Switzerland by the Making Electoral Democracy work project.