Do political preferences translate into behavior? I argue that when individuals support a stigmatized party, they have an incentive to conceal that support to avoid social sanctions. I provide real-world, causal evidence of this falsification of political preferences by leveraging a unique decision by the Electoral Commission in one region of Spain that made voting not private in one of four elections in the same day. Qualitative evidence shows that this decision made voters feel that their vote choice could be observed. Using cross-section linear regressions, difference-in-differences and triple differences, I show that this observability decreased voting for the right-wing party PP, which is stigmatized in the country. At the individual level, voters who support the party make more efforts to keep their vote choice secret. Those who make those efforts also show more discomfort answering surveys on politics. The results highlight social norms as predictors of political behavior, and show that seemingly minor changes to the voting procedure can affect electoral outcomes.