We develop a simple model of trade relations in which legislators with different stakes in import-competing and export industries decide whether to grant fast-track authority (FTA) to the president, giving up the power to amend international trade agreements. We show that strategic delegation motives are key to understanding FTA votes, which involve a decision between alternative country representatives: the executive or the majority in Congress. We then examine the determinants of all votes by US congressmen on FTA since the introduction of this institutional procedure in 1974. Our empirical analysis provides strong support for the predictions of the model.