Using surveys conducted in sixteen mature and newly established democracies around the globe, this study examines the effect of corruption on people's attitudes toward government. The analysis demonstrates that citizens in countries with higher levels of corruption express more negative evaluations of the performance of the political system and exhibit lower levels of trust in civil servants. However, the results also show that the negative effect of corruption on evaluations of the political system is significantly attenuated among supporters of the incumbent political authorities. These findings provide strong and systematic evidence that informal political practices, especially those that compromise important democratic principles, should be considered important indicators of political system performance. Moreover, they imply that, while corruption is a powerful determinant of political support across widely varying political, cultural, and economic contexts, it does not uniformly diminish support for political institutions across all segments of the electorate.