Incorporating Open Primaries Under the “Two Institutionalisms” Framework

Abstract

This article explores why some states adopt state-regulated open primary or internal election processes to select candidates for public office and which theoretical approach better explains this institutional change. Using Argentina and Uruguay as comparative case studies, it examines the introduction of Argentina’s PASO and Uruguay’s internal elections, focusing on party system fragmentation and on the incentives faced by governing parties when their hold on power is challenged. The analysis contrasts two strands of institutionalism: Historical Institutionalism, which stresses path dependence, institutional legacies and self-reinforcing dynamics, and Rational Choice Institutionalism, which highlights strategic actors, cost-benefit calculations and external shocks as triggers for reform. The paper argues that Rational Choice Institutionalism provides a more accurate account of why open and mandatory internal elections were incorporated into the electoral rules in both countries, while acknowledging that this explanation must be complemented with historical and contextual factors in order to understand how institutions both constrain and are reshaped by political actors.