A territorial connection? Explaining intra-party ideological diversity in France and Spain.

This paper focuses on a neglected aspect of the study of ideological divergences within political parties: the existence of different territorial layers within party organizations. We explore and explain the concept of intra-party ideological diversity (IPD), defined as the variety of ideological positions taken by Members of Parliament (MPs) with regard to their party at different levels of territorial organization. Using the principal-agent theory, as well as the literature on the territorial organization of political parties, we consider MPs as agents of competing principals: the constituents and the party at the local, regional and national levels. Their expectations on how their agent should behave are potentially contradictory. We measure IPD as a text-based distance between MPs and their party at different levels of organization, using Twitter data in a centralized country with a candidate-centred electoral system, France, and in a decentralized country with a party-centred electoral system, Spain, between 2016 and 2019. Overall, we find that IPD can mainly be explained by the variations of the electoral system and regional autonomy between and within countries, and by the relative electoral strength of MPs and their party principals. We distinguish between two situations: dissent and diversity. In the former, prevalent in France, legislators move away from their party as a whole when their institutional, party and local environment enables them to be re-elected independently from their party’s label. In the latter, prevalent in Spain, when the institutional, party and local environment does not favour the autonomy of MPs with regard to their party as a whole, they tend to move closer to the party principal the most likely to maximize their chances of re-election.