Abstract
Objective/context: This paper examines the open legal primary rule in Chile for the selection of the presidential candidate, established in 2012 through Law 20640. This rule contains elements shared with similar legislation in the region as well as specific characteristics. Methodology: Through a case study, we will investigate the results and consequences of the application of primaries on the three occasions they were implemented (2013, 2017, and 2021). We will review the formal changes adopted and the political events that occurred in the interim, considering the main variables that typically intervene in electoral events of this nature, drawn from the existing debate and literature. Conclusions: The case of Chile shows that the combination of an open legal primary system with voluntary internal voting, incomplete simultaneity, and the absence of stable political groupings produces effects that do not align with either the general aspirations for the implementation of primaries or the theoretical purposes outlined by the ideologists of Chilean legislation. Originality: This study contributes to the emerging literature addressing open legal primaries in their dual aspect, both as a nomination mechanism and as an electoral rule.