WASHINGTON – Capping a long and bitter race for the White House, Americans cast their votes Tuesday with polls showing President Barack Obama and Republican challenger Mitt Romney neck-and-neck in an election that will be decided in a handful of states. The fate of Obama and Romney was sealed in ballot boxes as at least 120 million people cast their votes. Their decision will set the country's course for the next four years on spending, taxes, healthcare and foreign policy challenges like the rise of China and Iran's nuclear ambitions. National opinion polls show Obama and Romney in a virtual dead heat, although the Democratic incumbent has a slight advantage in several vital swing states – most notably Ohio – that could give him the 270 electoral votes needed to win the state-by-state contest. Romney, the multimillionaire former head of a private equity fund, would be the first Mormon president and one of the wealthiest Americans to occupy the White House. Obama is vying to be the first Democrat to win a second term since Bill Clinton in 1996. Whichever candidate wins, a razor-thin margin would not bode well for the clear mandate needed to break the partisan gridlock in Washington. Romney voted at a community center near his home in a Boston suburb before dashing off for two last-minute stops, including the most critical of all swing states - Ohio. “I feel great about Ohio,” he said when asked about what is considered a must-win for him. Obama, settled into his home town of Chicago, made a final pitch to morning commuters with pre-recorded interviews broadcast in battleground states. “Four years ago, we had incredible turnout,” Obama told a Miami radio station. “I know people were excited and energized about the prospect of making history but we have to preserve the gains we've made and keep moving forward.” Fueled by record spending on negative ads, the battle between the two men was focused primarily on the lagging economic recovery and persistent high unemployment, but at times it turned personal. As Americans headed to voting booths, campaign teams for both candidates worked the phones feverishly to mobilize supporters to cast their ballots. The first results, by tradition, were tallied in Dixville Notch and Hart's Location, New Hampshire, shortly after midnight (0500 GMT). Obama and Romney each received five votes in Dixville Notch. In Hart's Location, Obama had 23 votes to nine for Romney and two for Libertarian candidate Gary Johnson. The close presidential race raises the prospect of a disputed outcome similar to the 2000 election, which was decided by the US Supreme Court in favor of George W. Bush over Al Gore. Both the Romney and Obama campaigns have assembled legal teams to deal with possible voting problems, challenges or recounts. The balance of power in the US Congress also will be at stake in Senate and House of Representatives races. – Agencies