Legislative Territorialization: The Impact of a Decentralized Party System on Individual Legislative Behavior in Argentina

The conventional understanding in the scholarly literature is that the main dimension that sets legislators’ ideal points is the tension between the government and the opposition parties. In this article, I challenge this claim, demonstrating that this alignment is contingent on the level of party system nationalization. These consequences have not been fully documented. Using DW-NOMINATE to calculate Argentine legislators’ ideal points (1983–2017), I show that individual territorialization in roll call voting increases when the party system is more decentralized. Legislators are closer to their provincial delegation, irrespective of which party they belong to, when there are low levels of party nationalization. At the individual level, this mechanism may be understood by the competing principals’ theory: because party system decentralization implies a response to local dynamics over national dynamics, cross-pressured legislators may favor their subnational principal.