Right-wing candidates have rallied against same-sex marriage, abortion, and ‘gender ideology’ in several recent Latin American elections, attracting socially conservative voters. Yet, these issues are largely irrelevant to voting decisions in other parts of the region. Drawing on theories explaining partisan shifts in the US and Europe, we argue that elite and social movement debates on sexuality politics create conditions for electoral realignment. When politicians take polarized positions on newly salient ‘culture war’ issues, the masses’ voting behaviour shifts. Using region-wide multilevel analysis of the AmericasBarometer and Latinobarómetro and a conjoint experiment in Brazil, Chile, and Peru, we demonstrate that the rising salience of sexuality politics creates new electoral cleavages, magnifying the electoral impact of religion and sexuality politics attitudes and shrinking the impact of economic views. Whereas scholarship on advanced democracies posits the centrality of partisanship, our findings indicate that sexuality politics prompts realignments even in weak party systems.