Americans are going to the polls to elect the next president. Opinion polls show President Barack Obama and his challenger, Mitt Romney in a virtual dead heat in a race that is expected to be decided in key swing states.
On election eve Monday night, President Obama and Romney, his Republican challenger, made their final campaign pitches to American voters.
"I've come back to Iowa one more time to ask for your vote. I came back to ask you to help us finish what we've started, because this is where our movement for change began," Obama told a crowd of 20,000 people in Des Moines.
Romney wrapped up his campaign with a late night rally in an indoor sports arena in Manchester, New Hampshire.
"Tomorrow is a moment to look into the future and imagine what we can do, to put that past four years behind us and build a new future," Romney said. "Walk with me. Tomorrow, we begin a new tomorrow."
At least 120 million Americans are expected to vote on Tuesday and their decision will set the country's course for the next four years.
National opinion polls show Obama and Romney in a virtual dead heat, although Obama has a slight advantage in several vital swing states - most notably Ohio - that could give him the 270 electoral votes he needs to win.
Most states tend to vote the same way but swing states are tossups because they do not lean in any particular direction and can change sides in any given election cycle.
The US election is not decided by the popular vote but rather state-by-state. Winning the popular vote in a state, even by a small margin, usually affords a candidate all of that state's votes in the Electoral College. A candidate needs 270 of these votes - allocated to states based on their population - to take the presidency.
Romney is scheduled to vote at home in Massachusetts on Tuesday morning before a final trip to Ohio and Pennsylvania. Obama, who voted in October, will spend the day at his home in Chicago.
The race is on
The first ballots of the 2012 election were cast in the tiny New Hampshire town of Dixville Notch, Tuesday with Barack Obama and Mitt Romney each receiving five votes.
The traditional first-in-the-nation vote, held shortly after midnight, was tied for the first time in its history. The split reflects the partisan divide that has Obama and Romney neck and neck.
The close presidential race raises concerns of disputed results similar to the 2000 election between Republican George W. Bush and Democrat Al Gore, which was decided by the US Supreme Court. Both campaigns have assembled legal teams to deal with possible voting problems, challenges or recounts.
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, the first black president, is vying for a second term.
hc/pfd (AFP, Reuters, dpa)