Obama Romney sprint to campaign finish

Barack Obama and Mitt Romney concluded their campaigning before Tuesday's presidential elections.

Barack Obama is welcomed to stage by Bill Clinton during a campaign rally in State Capitol Square in Concord, New Hampshire on 4 November 2012. AFP

NEW HAMPSHIRE: President Barack Obama and Republican challenger Mitt Romney sprinted to an unpredictable finish in the last 48 hours of a close White House race on Sunday, trying to turn out supporters and woo undecided voters in a handful of toss-up states.

The two rivals crisscrossed the country on the next-to-last day of a campaign that polls show is deadlocked nationally, although the president appeared to have a slight edge in the swing states that will decide who captures the 270 electoral votes needed to win on Tuesday.

After months of sometimes bitter attacks and saturation advertising in pivotal states, Obama and Romney pressed their arguments that they offer the best solution to a weak economy and partisan gridlock in Washington.

The two also made direct appeals for votes in a race that may come down to which side does the best job of getting its supporters to the polls.

"It's up to you. You have the power," Obama told a crowd of more than 14,000 people who filled the downtown streets of Concord, New Hampshire.

"You will be shaping the decisions for this country for decades to come, right now, in the next two days."

In Iowa, Romney urged more than 4,000 people in a Des Moines hall to get out and vote - and convince undecided or former Obama supporters to back him while they are at it.

At a later stop in Ohio, he said, "Let's make sure that we get everyone to the polls."

Romney, the former governor of Massachusetts, renewed his argument that he is the candidate who can offer change and reach out to the opposition party to craft bipartisan agreements.

"Accomplishing real change is not just something that I talk about. It's something that I've done," Romney told supporters in Des Moines.

"And it's something I'm going to do when I am president of the United States."

Many polls show Obama with a slight but persistent lead in Ohio, Wisconsin, Iowa and Nevada - states that would give him more than the 270 electoral votes he needs, barring any surprises elsewhere.

A Reuters/Ipsos poll of four pivotal states showed Obama and Romney essentially tied in Florida and Colorado, with Obama holding a statistically meaningless lead in Virginia of 1 percentage point.

But in crucial Ohio, Obama had 48 percent to Romney's 44 percent.

Both candidates were getting plenty of help in the late stages from their running mates, Joe Biden and Wisconsin congressman Paul Ryan.

Obama also got help at his New Hampshire rally from popular former President Bill Clinton.

Ryan joined fans holding tailgate parties outside a Green Bay Packers football game in Wisconsin, then visited Minnesota - another Democratic-leaning state where Romney is making a late play.

While campaigning in Ohio, Biden joked that the end of Daylight Savings Time in the United States on Sunday was Romney's favourite day because he could officially turn back the clock.