Trust in political institutions is in long-run decline across most advanced industrial democracies, but the consequences of this distrust for democracy are less clear. Previous studies on these consequences are limited in the topics they consider, and they are largely reliant on cross-sectional observational approaches which cannot identify causal relationships. One such overlooked topic is whether political distrust undermines support for democratic norms. While it has often been argued that political distrust threatens democratic legitimacy, previous work on support for democratic norms focuses instead on democratic discounting. In this paper, I conduct the first experimental test of how political distrust may reduce support for democratic norms in three ways: by prompting direct support for authoritarian values; by increasing intolerance for partisan out-groups; and by increasing support for antidemocratic behavior by partisan in-groups. In so doing, I provide the first causally rigorous test of whether we should be concerned about political distrust threatening democratic legitimacy.