SAN JUAN - Puerto Ricans head to the polls on Sunday to decide whether they want their struggling US territory to become the 51st US state, although a vote in favor would likely face an uphill battle in Congress and with President Donald Trump.The vote comes at a time of economic hardship for the island, hamstrung by $70 billion in debt, a 45-percent poverty rate, woefully underperforming schools, and near-insolvent pension and health systems.Puerto Rico's hazy political status, dating back to its 1898 acquisition by the United States from Spain, has contributed to the economic crisis that pushed it last month into the biggest municipal bankruptcy in US history."Statehood hasn't come in the past 120 years. Why would Donald Trump want to make this bankrupt island a state now? It will be another 120 years before that happens," said Miriam Gonzalez, a 66-year-old retiree in San Juan.Heading into the plebiscite, Puerto Ricans mingling on the quaint and narrow streets of old San Juan were divided over the three options they will face on Sunday's ballot: becoming a US state; remaining a territory; or becoming an independent nation, with or without some continuing political association with the United States.Under the current system, Puerto Rico's 3.5 million American citizens do not pay federal taxes, vote for U.S. presidents or receive proportionate federal funding on programs like Medicaid, though the US government oversees policy and financial areas such as infrastructure, defense and trade.Puerto Rico's recently elected governor Ricardo Rossello campaigned last year on holding a referendum.Rossello's New Progressive Party (PNP) party, which controls Puerto Rico's government, is premised on a pro-statehood stance, while the opposition Popular Democratic Party (PPD) supports versions of the current territory status and a third party, the Puerto Rican Independence Party (PIP), supports independence.A spokesman for the governor told Reuters he will push Congress to respect a result in favor of statehood, but Puerto Rico is seen as a low priority in Washington.The status referendum is Puerto Rico's fifth since 1967. Statehood won in the last referendum in 2012, though PPD leaders instructed constituents to leave blank hundreds of thousands of ballots, calling the result into question."Statehood isn't going to happen and the status quo is a trap," said 23-year-old engineering and economics student Daniel Montalvo. "At this point, I think gradual independence is the best option."