DANICA COTOSAN JUAN, Puerto Rico (AP) â¿¿ Puerto Ricans were facing a fundamental question on Election Day: Should they change their ties with the United States? Citizens in the U.S. island territory cannot vote in the U.S. presidential election, but many were excited to participate in a referendum that could help determine the island's political future, pushing it toward statehood, greater autonomy or independence. Car horns blared and party flags waved as voters headed to polling stations, some of them yelling their political preferences. Many carried umbrellas to shield themselves from a blistering tropical sun as temperatures neared 90 degrees Fahrenheit (31 degrees centigrade). The two-part referendum first asks voters if they want to change Puerto Rico's 114-year relationship with the United States. A second question gives voters three alternatives if they do want a change: become the 51st U.S. state, independence, or "sovereign free association," a designation that would give more autonomy for the territory of 4 million people. "Puerto Rico has to be a state. There is no other option," said 25-year-old Jerome Lefebre, who picked up his grandfather before driving to the polls. "We're doing OK, but we could do better. We would receive more benefits, a lot more financial help. Let's finish what we started." But 42-year-old Ramon Lopez de Azua said he favors the current system, which grants U.S. citizenship but prevents Puerto Ricans from voting for U.S. president and gives the island only limited representation in Congress. "Puerto Rico's problem is not its political status," he said. "I think that the United States is the best country in the world, but I am Puerto Rican first." Both President Barack Obama and presidential candidate Mitt Romney have said they supported the referendum, with Obama pledging to respect the will of the people if there is a clear majority. Any change would require approval by the U.S. Congress.