News In Depth
US heads to poll in tight race
US President Barack Obama and Republican challenger Mitt Romney have left voters on election day with a stark choice between their fundamentally different visions for the country's future, laid out during an aggressive and closely fought battle for the White House.
Both sides cast the 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.
After months of campaigning and billions of dollars spent in the battle for leadership of the world's most powerful country, Mr Obama and Mr Romney were in a virtual nationwide tie, a symptom of the country's vast partisan divide.
Mr Obama appeared to have a slight edge, however, in some of the key swing states such as Ohio that do not vote reliably Democrat 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," Mr Obama said. "Because until people actually show up at the polls and cast their ballot, the rest of this stuff is all just speculation."
Mr Romney told Ohio voters to remember as they go to the polls that the country is hurting financially under Mr Obama's policies. "If it comes down to economics and jobs, this is an election I should win," Mr Romney said.
Mr Romney cast his vote near his Massachusetts home. The Republican challenger still had election day rallies in Ohio and neighbouring Pennsylvania, traditionally Democratic territory where Mr Romney has made a surprise and last-minute push - perhaps against all odds - to compensate for Mr Obama's expected victory in Ohio.
Mr Obama voted last month, a move intended to encourage early voting that tends to favour Democrats.
The president was spending election day in his home town of Chicago, where he was met with applause and tears from volunteers as he entered a campaign office before picking up a phone to call voters in Wisconsin. He later congratulated Mr Romney "on a spirited campaign" and told reporters he is "confident we've got the votes to win."
Under the US 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 2000, when the outcome was not known for weeks after a recount in Florida and a Supreme Court decision. A narrow victory for either candidate is sure to deepen polarisation and leave the winner without a strong mandate to face mounting problems - most pressingly, averting the "fiscal cliff" of higher taxes and deep automatic cuts in spending looming in January.
It is not just the presidency at stake: all 435 seats in the House of Representatives, a third of the 100 Senate seats, and 11 governorships are on the line, along with state ballot proposals on topics ranging from gay marriage to legalising marijuana. Democrats were expected to maintain their majority in the Senate, with Republicans doing likewise in the House, raising the prospect of continued partisan wrangling no matter who might be president.
Mr Obama's final campaign rally on Monday night in Iowa was filled with nostalgia as he returned to the state which launched him on the road to the White House in 2008 with a victory in the race for the Democratic nomination.
There has been little of the euphoria that propelled Mr Obama to the White House four years ago, with America's first black president promising hope and renovation to a nation weighed down by war and a near financial meltdown.
The economy has proven a huge drag on Mr Obama's candidacy as he fought to turn it around after the deepest recession since the Great Depression of the 1930s, a downturn that was well under way when he replaced George W Bush in the White House.
He ended the war in Iraq and the US intelligence and military tracked down and killed Osama bin Laden, but a new host of Middle East crises - especially the war in Syria and the deadly attack on the US Consulate in Libya - shadowed the last months of the campaign.
Mr Romney, 65, has attacked Mr Obama's economic policies amid the recession and promised to bring change that he asserted Mr Obama had only talked about.
If elected, Mr Romney would be the first Mormon US president.
His strong performance during the first presidential debate in September turned around a campaign that had been stumbling over the summer - including a gaffe-filled trip abroad - and he has worked carefully ever since to keep up the momentum and avoid new mistakes.
After voting, he was asked who he voted for. He said with a smile, "I think you know."
The final Washington Post-ABC News tracking poll, released on Monday, showed Mr Obama with support from 50% of likely voters to 47% for Mr Romney.
More than 30 million absentee or early ballots have already been cast, including in excess of three million in Florida.
In surveys of the battleground states, Mr Obama held small advantages in Nevada, Ohio, Iowa and Wisconsin - enough to deliver a second term if they held up, but not so significant that they could withstand an election day surge by Romney supporters.
Mr Romney appears to be performing slightly better than Mr Obama or has pulled even in North Carolina, Virginia and Florida.
The biggest focus has been on Ohio, an industrial state that has gone with the winner of the last 12 presidential elections, which both candidates visited on Monday. No Republican has ever won the White House without carrying Ohio.
Election Day turnout was heavy in several storm-ravaged areas in New York and New Jersey, with many voters expressing relief and even elation at being able to vote at all, considering the devastation from Superstorm Sandy.