Under the U.S. Constitution, Puerto Rico could legally be a territory belonging to the United States, as it currently is. It could also be an independent nation or a state. All three are possible relationships between the United States and Puerto Rico, under the law. But Congress has the legal power to define the relationship. Congress cannot create a new relationship not contemplated by the Constitution, but Congress can refuse to allow Puerto Rico to be in any of those relationships.
Congress is not required by law to ask the permission of people living in a territory before admitting that territory as a state, proclaiming its independence, or keeping it on as a territory, but Congress usually does consult the people living in a territory to get their opinion, and they have never yet permanently refused to admit a territory which asked for statehood. So, if the voters of Puerto Rico were to choose independence, would Congress agree?
Congress has refused to allow independence before
Vermont declared independence in 1777. They were part of New York, a colony of Great Britain, and they declared their independence from both New York and Great Britain, setting themselves up as an independent nation. New York did not agree. The Continental Congress, the forerunner of the U.S. Congress, also refused to accept their independence from New York. Great Britain, of course, was not accepting the separation of any of the American colonies. Vermont’s Declaration of Independence was actually a strategic move toward statehood, and they became a state of the Union in 1791, after agreeing to pay New York for the loss of territory.
West Florida, which had been a colony of Great Britain, declared independence in 1810. Great Britain had agreed to give the land back to Spain, but the U.S. said that it had been part of the Louisiana Purchase. The Louisiana Purchase, an enormous territory bought from France, had uncertain borders at the time, and Spain and the United States spent years working out the details. Just about three months after West Florida’s declaration of independence, the United States sent military forces in and deposed the fledgling government.
The California Republic had an even shorter history. Part of what is now the state of California declared independence from Mexico in 1846, but welcomed U.S. military 25 days later, disbanded their new nation, and went for statehood instead.
In fact, none of these examples were territories demanding independence from the United States. They were colonies of other nations declaring independence from those nations, and the United States stepped in to annex them.
There was one U.S. territory that might be said to have declared independence. One Minnesota newspaper printed a declaration of independence from the United States in 1858, but the territory was admitted as a state just days later. That is the only case of a territory belonging to the United States calling for independence, and it did not, like the examples mentioned earlier, include a new constitution or any military action. It might fairly be described as a political publicity stunt.
When the Confederate states seceded, precipitating the Civil War, they were declaring independence from the United States. The U.S. did not agree, and President Lincoln announced that states couldn’t be separated from the Union. The Senate debated the question, but ended up expelling senators from the Confederate states. The Supreme Court settled the question by deciding that states did not have a legal right to secede. Civil war ensued. Following the war, some members of Congress proposed that the former states should be made territories. These representatives believed that the Southern states had given up their statehood by seceding and should have to start over as territories and work their way back to admission. That view was a minority position, though; the majority agreed that the Confederate states had never really succeeded in leaving the United States in the first place and therefore should be allowed back into the Union without those formalities.
The United States Congress could refuse to allow Puerto Rico to become independent. Just as Congress has failed to take action on the Island’s votes in favor of statehood, it could ignore a vote from Puerto Rico for independence. But would it?
Congress has also allowed independence
Congress accepted independence for the Philippines, Cuba, and the Trust Territory of the Pacific Islands which became three independent nations. These are all the territories that have actually requested independence from the United States.
Congress has also considered bills for independence for Puerto Rico in the past. The Tydings Bills of 1936 and 1946 were probably the closest to succeeding, but neither was passed in Congress, nor did Puerto Rico’s territorial government approve them. The most recent was a bill introduced by Luis Gutierrez (D-IL) in 2017, which died in committee with no cosponsors.
The responses to these and similar bills suggest that Congress has not been any more enthusiastic about independence for Puerto Rico than the voters of Puerto Rico have, but the debates have not included discussions of refusing Puerto Rico independence. The hearings on the Tydings bill of 1946 featured insistence by the U.S. military that any agreement on independence should include military access by the United States to Puerto Rico, but did not involve refusals to allow independence in principle.
History suggests that, while the United States has been willing to ignore declarations of independence from foreign territories and from its own states, it does not refuse independence to U.S. territories that want independence. Puerto Rico has never voted for independence in any referendum, has never elected any governor or resident commissioner from the Independence Party, and has never shown a desire for independence.