How Does May’s Law Work in Multi-dimensional Competition? Intra-party Opinion Structure in Catalonia

Abstract This article explores how multi-dimensional competition party systems shape the intraparty opinion structure in political parties. The aim is to extend and test May’s law of ideological curvilinear disparity to multi-dimensional settings. The data are based on the case of Catalonia, a party system characterized by the relevant presence of non-state wide parties, where political competition is based on two main dimensions: the left right axis and the subjective national identity one. The paper shows that while the Catalan parties do fit with May’s law in the left-right axis, this is not the case in the national identity one. In addition, it further illustrates how the interaction between both axes affects party competition and internal opinion differences between leaders, activists and voters. The results attest the complexity of the intraparty opinion structures in multidimensional competition systems.