WASHINGTON - President Barack Obama and Republican rival Mitt Romney engaged in a frenzied cross-country blitz of the remaining toss-up states Sunday, with both sides predicting victory in a race that remains too close to call just two days before Election Day.
National opinion polls showed a race for the popular vote in Tuesday's election so close that only a statistically insignificant point or two separated the two rivals.
But the majority of polls in the battleground states — especially in the Midwestern states of Iowa, Wisconsin and Ohio — showed Obama with a slight advantage, giving him an easier path to the 270 electoral votes needed for victory. No Republican has won the White House without carrying Ohio.
Under the U.S. system, the winner is not determined by the nationwide popular vote but in state-by-state contests, making "battleground" states that are neither consistently Republican nor Democratic extremely important in such a tight race. Romney and Obama are actually competing to win at least 270 electoral votes. The electoral votes are apportioned to states based on a mix of population and representation in Congress.
That raises the possibility of a replay of the 2000 election when Republican George W. Bush won the presidency with an electoral vote majority, while Democrat Al Gore had a narrow lead in the nationwide popular vote.
The final national NBC/Wall Street Journal Poll, conducted from Nov. 1-3, showed Obama getting the support of 48 per cent of likely voters, while Romney receives 47 per cent. The poll had a margin of error of 2.55 percentage points.
The final frenzy of campaigning comes in the wake of Superstorm Sandy that devastated the U.S. East Coast. It gave Obama a chance to jump into action as commander in chief and show bipartisanship by working with Republican state officials such as New Jersey Gov. Chris Christie and left Romney struggling to strike the right tone.
The economy has been the dominant issue of the campaign despite detours into foreign policy and social issues. At week's end, the final jobs report before Tuesday's election gave one last economic snapshot, showing the U.S. adding a solid 171,000 jobs and more than a half-million Americans joining the workforce. But the jobless rate of 7.9 per cent was still higher than when Obama took office.
Obama's campaign hoped to gain an edge in the tight race by mobilizing a massive get-out-the-vote effort aimed at carrying the Democrat to victory. Obama had a full schedule Sunday, with campaign stops in New Hampshire, Florida, Ohio and Colorado.
The president caught a few hours of sleep back at the White House Saturday night before hitting the campaign trail again Sunday. Obama won't return to the executive mansion again until after Election Day.
Romney's campaign was projecting momentum and banking on late-breaking voters to propel him to victory in the exceedingly close race. Romney's political director, Rich Beeson, optimistically suggested Sunday that Romney could earn more than 300 electoral votes on Election Day.
Romney began Sunday with a campaign rally in Des Moines, Iowa, and also planned stops in Ohio and Virginia.
The Republican was also cutting away briefly Sunday from the nine or so competitive states that have dominated the candidates' travel itineraries to make a late play for votes in Pennsylvania, a Democratic-leaning state.
Romney has shifted sharply in recent weeks to appeal to the political centre and highlights what he says was his bipartisan record as governor of Democratic-leaning Massachusetts. Romney, who during the Republican primary campaign once described himself as "severely conservative," is aggressively courting the narrow slice of undecided voters — largely women and moderates — who have yet to settle on a candidate.
Making his closing case to voters Sunday in Des Moines, Iowa, Romney pledged, if elected, to work with Democrats to restore the American dream and bring the economy roaring back to life.
"We're Americans. We can do anything," Romney said. "The only thing that stands between us and some of the best years we can imagine is a lack of leadership — and that's why we have elections."
In the final days of his final campaign, Obama has been imploring crowds at his rallies — and the wider electorate — to let him finish what he started. The nation has been bruised by recession and war, he contends, but remains resilient and is coming back.
Obama, too, said he is willing to work across party lines to break Washington's gridlock, but assured some 14,000 supporters who gathered in Concord, New Hampshire, that he would not compromise key Democratic priorities such as health care and college financial aid.
"I know I look a little bit older, but I've got a lot of fight left in me," Obama said. "We have come too far to turn back now. We have come too far to let our hearts grow faint. It's time to keep pushing forward."
The president's rallies are aimed at boosting Democratic enthusiasm and motivating as many supporters as possible to cast their votes, either in the final hours of early voting or on Election Day.
Obama's campaign said it had registered 1.8 million voters in key battleground states, nearly double the number of voters they registered in 2008. Campaign officials said volunteers had made 125 million personal phone calls or door knocks with voters.
Even as he dashed from campaign stop to campaign stop, Obama was careful to avoid the perception he had taken his eye off recovery efforts from Superstorm Sandy. As Obama flew Sunday from Washington to New Hampshire, White House spokesman Jay Carney said the president was getting regular updates and would have a full briefing from top officials, including Homeland Security Secretary Janet Napolitano, who was in New Jersey on Sunday to view storm damage.
Former President Bill Clinton, who has joined Obama on the trail for the waning days of the race, called Obama's handling of the storm a clear example that the president has the right philosophy about how to fix the nation's messes.
"It was a stunning example of 'we're all in this together' is a way better philosophy than 'you're on your own,'" Clinton said as he introduced Obama in Concord.
Both candidates were drawing large crowds as they dropped in and out of the most competitive states. Obama and Clinton drew 24,000 people to an outdoor rally in Bristow, Virginia, on a cold Saturday night. Romney's Friday night rally in Ohio drew more than 20,000 people.
With Obama maintaining a slight lead in Ohio, the Romney campaign sought to make a last-minute play for Pennsylvania, a state which the Democratic candidate has won in the last five presidential contests.
Romney, along with running mate Paul Ryan, had an early evening event planned in Morrisville, Pennsylvania, his first rally in the state this fall.
Romney's visit follows the decision by his campaign and its Republican allies to put millions of dollars in television advertising in Pennsylvania during the race's final weeks. Obama's team followed suit, making a late advertising buy of its own and scheduling appearances across the state by Clinton for Monday.
The Republican ticket cast the late push into Pennsylvania as a sign that Romney had momentum and a chance to pull away states that Obama's campaign assumed it would win handily. Obama senior adviser David Plouffe told "This Week" that Romney's move was "a desperate ploy at the end of a campaign," given the Democrats' million-voter registration advantage in Pennsylvania.
More than 27 million Americans have already voted in 34 states and Washington, D.C. Obama holds an apparent lead over Romney in several key states such as Iowa and Nevada. But Obama's advantage isn't as big as the one he had over John McCain four years ago, giving Romney hope that he could make up that gap in Tuesday's voting.
Associated Press writers Julie Pace and Josh Lederman in Washington, Kasie Hunt in Englewood, Colorado, and Steve Peoples in Des Moines, Iowa, contributed to this report.