What is the role played by immigrant groups in shaping migration policy in the destination country? We address this question exploiting cross-state variation in U.S. citizens' access to the franchise, due to the presence of residency requirements. First we document that naturalized immigrants were more geographically mobile than natives. Second, congressmen representing districts with large numbers of naturalized U.S. citizens were more likely to support an open migration policy, but this effect is reversed once we account for residency requirements. Our results indicate that electoral accountability of U.S. congressmen to naturalized immigrants was a key factor in explaining this outcome.