Washington, Nov 6 (IANS) President Barack Obama appeared to have a slight edge over Republican challenger Mitt Romney as America headed for the polls to pick the winner of a White House race that has remained extremely close for weeks.

Taking no chances, both Obama and Romney and their key campaigners spent the final hours leading to Tuesday' poll dashing across electoral battlegrounds in Florida, Nevada, Colorado, Ohio, Wisconsin, Iowa, Virginia and New Hampshire.

Romney, according to a campaign official, will keep campaigning on Election Day, adding stops in Democratic-heavy Cleveland and Pittsburgh.

Seven of the eight national polls released since Sunday indicate the race for the White House is not only in a dead heat nationally, but also in the key battleground states that will decide the next tenant of the White House, according to CNN.

According to the final CNN/ORC International poll released Sunday night, 49 percent of likely voters support the president, with an equal number backing the former Massachusetts governor.

A Politico/George Washington University survey has the race tied at 48 percent. An NBC News/Wall Street Journal poll indicates Obama at 48 percent and Romney at 47 percent.

The latest ABC News/Washington Post tracking poll puts Obama at 49 percent and Romney at 48 percent; Gallup's latest daily tracking poll had Romney at 49 percent and Obama at 48 percent.

American Research Group had it deadlocked at 49 percent and Monmouth University had it all tied up at 48 percent. A Pew Research Centre survey released Sunday indicates the president at 50 percent and the challenger at 47 percent, which is within the survey's sampling error.

However, despite the close polls nationally, looking at the polls in key battleground states many analysts give Obama better odds to reach the magic number of 270 in the 538-member Electoral College.

FiveThirtyEight, a respected blog run on the New York Times by a former baseball stastician Nate Silver, for one, upped Obama's share by eight points to 314.4 giving him a 91.4 percent chance of victory with a 50.9 percent vote to Romney's 48.2 percent.

"If President Obama wins re-election on Tuesday, the historical memory of the race might turn on the role played by Hurricane Sandy," he said calling it an "October surprise" that allowed Obama to regain his footing after stumbling in the first presidential debate.

"Obama led in the vast majority of battleground-state polls over the weekend. And increasingly, it is hard to find leads for Romney in national surveys - although several of them show a tie," Silver wrote.

Politico, another influential site that focuses on presidential politics too raised Obama's Electoral College share to 303 including 66 swing state votes from 290 Sunday.

The Real Clear Politics, a political news aggregating side, also increased Obama's average advantage by a point to 48.8 percent, just 0.7 percentage points ahead of Romney. But it stuck to its forecast of 206 votes for Obama to Romney's 191 with 146 too close to call.

(Arun Kumar can be contacted at arun.kumar@ians.in)