Puerto Rico has been a U.S. territory since 1898. Its residents are U.S. citizens by statute (since 1917) but cannot vote in presidential elections and have only a non-voting Resident Commissioner in the House. The Insular Cases (1901-1922) created a doctrine of "unincorporated territories" subject to less-than-full constitutional protection — a doctrine many legal scholars consider vestigial.
Puerto Ricans have voted in non-binding plebiscites multiple times. The 2020 plebiscite showed a narrow majority for statehood (52%); turnout and ballot-design questions complicate interpretation. Independence and free-association options have minority support.
Congress has constitutional authority to admit Puerto Rico as a state, recognize independence, or restructure its territorial status. Recent bipartisan bills propose binding plebiscites limited to non-territorial options.