In transitional democracies like Argentina and Chile, denialist rhetoric—discourse that minimizes or justifies human rights violations committed by past authoritarian regimes—poses a subtle threat to democratic norms. How do voters respond to such rhetoric, and why? The polarization literature suggests that centrists will sanction it, while right-wing voters will remain loyal. I argue, however, that right-wing reactions depend on whether a cohesive and widely shared collective memory of authoritarianism centered on rejecting human rights violations was institutionalized. Where such memory became dominant, right-wing voters are likely to interpret denialism as antidemocratic, attach a high value to democracy with human rights as a core component, and punish such appeals. But where memory remains contested, punishment is unlikely to emerge. Using original survey experiments, I find that while centrists consistently punish denialist candidates in both countries, right-wing responses diverge: in Argentina, denialist rhetoric is penalized and seen as anti-democratic; in Chile, it is neither punished nor recognized as such. I trace the distinct historical trajectories of memory institutionalization with case studies, and illustrate how voters interpret denialism and democracy with focus group discussions.