Around the world, citizens express strong support for democracy, yet many also back anti-democratic leaders and parties. We argue this that seeming paradox can partly be explained by the social nature of democratic support: Citizens’ support for democracy and democratic principles is shaped by social norms about democracy, sensitive to social pressure and therefore malleable to different environments. This study draws on lab experiments to directly explore how social norms and environments influence citizens’ democratic preferences and behavior in a controlled environment where citizens interact in-person. In the lab, we elicit norms related to democracy and anti-democratic behavior, then manipulate social settings to examine how preferences shift in public versus private contexts and under varying perceptions of social norms. We also use interactive behavioral games to assess participants’ willingness to punish anti-democratic actions by others and conduct group discussions to explore the dynamics of social pressure and norm enforcement. Complementing the lab, we also use online surveys to measure social norms surrounding democracy and evaluate citizens’ willingness to conform to perceived changes in these norms in a broader sample of citizens. Our study yields insight into whether the perceived collective adherence to democracy in many societies depends on perceived social norms, and thereby vulnerable to perceived shifts in social environments and norms.