President Barack Obama and Republican challenger Mitt Romney left Americans to vote Tuesday with a stark choice between their fundamentally different visions for the country's future after an aggressive and closely fought battle for the White House. The winner might not be known until the next morning.
Both sides cast the Election Day decision as one with far-reaching repercussions for a nation still recovering from the biggest economic downturn since the Great Depression and at odds over how big a role government should play in solving the country's staggering debt and high unemployment.
In a Castanet poll asking 'Who do you think will be victorious in Tuesday's Presidential election' 85% thought President Obama would win.
In the U.S. the polls are deadlocked. After months of campaigning and billions of dollars spent in the battle for leadership of the world's most powerful country, Obama and Romney were in a virtual nationwide tie, a sign of the country's vast partisan divide.
Obama appeared to have a slight edge, however, in some of the key swing states such as Ohio that do not vote reliably Democratic or Republican. That gives him an easier path to reach the 270 electoral votes needed to win the presidency.
"I feel optimistic, but only cautiously optimistic," Obama said on "The Steve Harvey Morning Show."
Later in the day, Obama eased the tension of waiting for the vote count playing basketball with friends at the White House.
At midday, Romney and running mate Paul Ryan met in Cleveland for a campaign stop in the state that could be the most crucial battleground of all, Ohio. The Midwestern industrial state has chosen the winner of the last 12 presidential elections, and no Republican has ever won the White House without carrying it.
Reflecting the state's importance, Vice-President Joe Biden made an unannounced stop in Cleveland to play defence, arriving at the airport just before Ryan's charter came in for a landing. Biden left the tarmac without comment to the surprised media travelling on his plane.
Romney, who cast his vote near his Massachusetts home Tuesday morning, still had a rally in Pennsylvania, traditionally Democratic territory where the Republican has made a surprise last-minute push, perhaps against all odds, to compensate for Obama's expected victory in Ohio.
Obama voted last month, a move intended to encourage early voting that tends to favour Democrats.
Under the U.S. system, the winner of the presidential election is not determined by the nationwide popular vote but in state-by-state contests. The candidate who wins a state, with Maine and Nebraska the exceptions, is awarded all of that state's electoral votes, which are apportioned based on representation in Congress.
The close race raised the possibility of a repeat of the 2000 election, when the winner, George W. Bush, was not known for weeks after a protracted recount in Florida and a Supreme Court decision. A narrow victory for either candidate this time is sure to deepen polarization and leave the winner without a strong mandate to face mounting problems.