VOTERS may have voted for more of the same in America on election day, but in Puerto Rico they opted for decisive change. In a two-stage plebiscite—the island’s fourth referendum regarding its relationship with the United States—54% of the electorate voted to change Puerto Rico’s current status as a self-governing “commonwealth”, and 61% wanted the new form of government to be full American statehood. It was the first time a majority of boricuas, as the islanders are known, has voted to become the 51st state. In both the last two plebiscites, held in 1993 and 1998, only 47% chose that option.

The United States gained control of Puerto Rico in 1898, following the Spanish-American War. Puerto Rico set up its own government in 1952, and its residents do not pay federal income taxes to Washington on their local earnings. Nonetheless, it is still effectively a colony: boricuas are subject to American law even though they cannot vote for president or Congress.

Puerto Ricans broadly agree on their preferred status: in a 1967 referendum, 60% voted for a commonwealth they were told would be gradually enhanced. In this scheme, they would keep their American citizenship, currency, defence and tax exemptions, But they would also receive long-sought-after improvements, possibly including a “compact” making their relationship with the United States permanent. They might also gain the right to control immigration, sign treaties, act independently in international groups and choose which federal laws (such as the minimum wage) would apply to them.

Unfortunately, this proposal is legally flawed. According to Christina Duffy Ponsa of Columbia Law School the only permanent way of belonging to the United States is through statehood. Any other status approved by one Congress could be revoked later. Similarly, Congress could exempt Puerto Rico from any given law, but could not let the island exclude itself from federal legislation at will. A presidential task force has concluded that the only permissible status options are statehood, free association, continuation of the current commonwealth status or independence.

As a result, when the ruling pro-statehood party won a legislative vote last year to hold a new referendum, it did not put “enhanced commonwealth” on the ballot. Residents were first asked whether to continue with the current arrangement, and then what other form of government they would prefer: statehood, independence or “sovereign free association”, a voluntary, reversible collaboration with the United States that has been adopted by some Pacific island groups. Supporters of the status quo could choose a second-best option, but many left the second question blank.

Support for statehood has increased over the years, as ties between the island and the mainland grow closer. There are now more boricuas in the continental United States than in Puerto Rico itself, and American film, television and sports have gained popularity. Moreover, because of the Earned Income Tax Credit, a cash-transfer scheme for the working poor, many Puerto Ricans would gain more than they lose by becoming subject to federal income tax. But even among the rich and among Puerto Ricans without close links to the rest of the United States, the framing of the question ensured that statehood would prevail among the options for change. Both independence and sovereign free association would have put the islanders’ American citizenship at risk.

The vote will not have immediate consequences. Congress would have to pass a law admitting Puerto Rico for it to become a state. With a fiscal squeeze looming at the start of 2013 lawmakers will have their hands full in the coming months. And the island’s government is unlikely to push the issue aggressively following the election as governor of Alejandro García Padilla, who supports a continued commonwealth.

Moreover, the Republican-controlled House of Representatives has little incentive to address the topic. According to exit polls, 83% of boricuas on the mainland voted for Barack Obama. Statehood would add two Senate seats and a House delegation of five, the same size as Oregon’s and probably as reliably Democratic.

Unless the island holds another vote that yields a different result, however, Puerto Rico has now officially requested statehood. If Democrats retake the House in 2014, they would be well-advised to try to add a 51st star to the flag.