Although scholars have begun to explore the determinants of public attitudes toward trade policy, we still do not know whether these attitudes have policy consequences. This paper presents the first systematic analysis of this question. I find that higher public support for free trade leads to lower tariffs, but only in democracies. I also find that democracy leads to lower tariffs only where public support for free trade is relatively high. Hence, although both public opinion and regime type are important, neither matters independently of the other. This finding suggests a need for further research on the conditional effects of both.