Private politics occurs when citizens and activists seek policy change outside the democratic legislative process. This includes boycotting companies and/or buycotting products so as to influence market practices (e.g., increased wages, more attention to environmental impact). The rise of private politics complicates our understanding of democratic responsiveness — legislators may be less incentivized to respond to citizens' preferences. This occurs because legislators receive less credit for policy change and may view themselves as less necessary for policy-making. We present a survey experiment with state legislators to explore how legislators react to private politics. We find that a constituent communication that references private politics vitiates legislative responsiveness. In particular, Republicans become less likely to say they would take policy action or move their positions. Moreover, reference to private politics decreases the likelihood of constituent engagement among both Republican and Democratic legislators. Our results accentuate the importance of considering private politics in conversations about how democracies work.