What factors determine firms' attitudes toward trade policy? This paper considers producers' policy preferences and political behavior in light of two key patterns in modern international trade: industries that face import competition often have many exporters, and foreign sales are concentrated in the hands of a small number of "superstar" exporters. Using a new survey of Costa Rican firms matched to systematic firm-level data on export behavior, we find that firm features are generally more important predictors of attitudes toward trade liberalization than industry-wide comparative advantage. We also show that export intensity is strongly associated with interest and lobbying activity on trade policy. The largest exporters, who are the strongest supporters of global integration, dominate trade politics. [web URL: http://www.journals.uchicago.edu/doi/abs/10.1086/687207]