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? I argue that electoral punishment of denialist appeals requires two conditions: voters must recognize these appeals as anti-democratic and place a high value on democracy understood to include respect for human rights. While existing research usually treats both the recognition of anti-democratic behavior and the value attached to democracy as given, I show that both vary across voters and contexts. Moreover, the polarization literature would predict that centrists sanction denialist rhetoric voiced by right-wing politicians, while conservative voters remain loyal. Instead, I argue that right-wing responses depend on whether an official collective memory of authoritarianism centered on rejecting human rights violations became politically dominant. Where this occurred, right-wing voters are likely to interpret denialism as anti-democratic and punish such appeals; where memory remains contested, punishment is unlikely. I treat collective memory as an endogenous historical process shaped by regime performance, transition type, transitional justice, and the persistence of authoritarian successor parties. Using original survey experiments, I show that centrists penalize denialist candidates in both countries, while right-wing voters diverge—punishing denialism because of its anti-democratic nature in Argentina but not in Chile. I link these differences to distinct trajectories of collective memory through comparative case studies and use focus group discussions to illustrate how voters interpret denialism and democracy.