Are there noticeable differences among political parties in a country over their trade policy positions? Do left parties advocate different trade policies than right parties? In the advanced industrial countries where labor tends to be scarce, are left parties more protectionist than right ones, which represent capital owners? Political institutions within these democratic countries may affect the role of partisanship. We also investigate whether increasing globalization has led to more or less partisan polarization over trade policy. We examine 25 developed countries from 1945 to 1998 to see how their parties have competed over trade policy. Controlling for various factors, partisanship matters. Right parties consistently take more free trade stances than do left ones. Globalization and other international forces have also shaped both the nature and the extent of the domestic debate over exposure to international trade.