Puerto Ricans have been U.S. citizens since 1917, and can move freely between the island and the mainland. However, as residents of an unincorporated territory, American citizens in Puerto Rico are disenfranchised at the national level, do not vote for the president or vice president, and generally do not pay federal income tax. As it is not a state, Puerto Rico does not have a vote in the U.S. Congress, which governs it under the Puerto Rico Federal Relations Act of 1950. Puerto Rico is represented federally solely by one non-voting member of the House called a "Resident Commissioner." Congress approved a local constitution in 1952, allowing U.S. citizens residing on the Island to elect a governor. Puerto Rico's future political status has consistently been a matter of significant debate.