Even where a public consensus exists about the appropriate bounds of constitutional action, citizens’ capacity to punish executive overreach is not guaranteed. People often lack information about possible constitutional transgressions, and imposing meaningful political penalties for overreach requires coordinated action among citizens. We argue that courts are key to overcoming these obstacles: under the right conditions, courts, through the use of judicial review, are uniquely positioned to alert the public of constitutional transgressions and thereby transform the public’s support for the rule of law into a guardrail against executive overreach. We suggest judicial independence enhances the ability of courts to signal that an executive has gone too far. By contrast, courts with low levels of judicial independence are impotent: their decisions are not credible enough to affect citizens’ attitudes. We also expect the rulings of independent courts to be most effective among citizens who have a high level of support for the rule of law and to persist even in the face of stark partisan polarization.