Ideological extremism, left-right orientations, and invalid voting in two-round presidential elections in Latin America

Abstract

ABSTRACT Ideology is one of the most studied factors affecting voting behavior in modern mass democracies. Despite that, literature on invalid voting has focused on other explanatory factors at the aggregate and individual levels. This article argues that ideology is a relevant explanatory factor affecting invalid voting at the individual level and advances two hypotheses. Specifically, voters with known preferences on the left-right dimension and those further from the center will be less prone to cast an invalid ballot in presidential elections. I test these hypotheses in the first and second rounds of nine presidential elections in four Latin American countries between 2002 and 2019. Additionally, the hypotheses were tested for voters caught in the runoff dilemma, i.e. those who did not vote for one of the two candidates who advanced to the second round. Using the Comparative Study of Electoral Systems data, the analysis confirms that left-right orientations and ideological extremism are negatively associated with the probability of casting an invalid vote. The article’s findings help expand our knowledge about how some specific features of ideology affect voting behavior, thus contributing to the literature on ideological and invalid voting.