Puerto Rico v. Sánchez Valle, 579 U.S. 59 (2016)

In Puerto Rico v. Sánchez Valle (2016), the U.S. Supreme Court confronted the fundamental question of Puerto Rico's sovereignty. The case involved the double jeopardy clause: could Puerto Rico and the federal government both prosecute the same person for the same conduct?

Under the "separate sovereigns" doctrine, two prosecutions for the same act are permitted if the laws under which they are brought derive from different sovereign sources. The question was whether Puerto Rico qualified as a separate sovereign from the United States.

The Court ruled 6-2 that Puerto Rico does NOT possess independent sovereignty. Justice Elena Kagan wrote for the majority: "[T]he Commonwealth's authority to create and enforce its own criminal law ultimately derives from Congress, which... wields plenary authority over Puerto Rico."

This was a devastating ruling for those who had argued that the Commonwealth, established in 1952, represented a genuine act of self-determination. The Court confirmed what critics had long argued: that Public Law 600 and the Puerto Rican Constitution did not change the fundamental colonial relationship. Puerto Rico's power comes from Congress, not from the people of Puerto Rico.

Justice Stephen Breyer's dissent argued that the history of Public Law 600 showed Congress intended to cede sovereignty to Puerto Rico, but the majority was unpersuaded.

The decision effectively stripped away the last legal fiction that the Commonwealth was anything other than a colonial arrangement.