By Arun Kumar

Washington, Oct 27 (IANS) As Barack Obama and Mitt Romney remained locked in a neck and neck race, poll watchers raised the possibility of Republican challenger winning the popular vote, but the president keeping the White House.

Even as ten new national polls showed a tied race, FiveThirtyEight, an influential poll forecasting blog on the New York Times, suggested that Obama maintains a narrow lead in the polling averages in states that would get him to 270 electoral votes needed to win the presidency.

On the basis of the new polls in the states, FiveThirtyEight gave Obama a 74.4 percent chance of a win with 50.3 percent vote as it raised its projection of the president's share of electoral votes to 295.4.

But Politico, another news site focused on politics, kept its projection of a 281-257 advantage for Obama unchanged. So did political news aggregating site RealClearPolitics giving Obama 201 votes to Romney's 191 with 146 too close to call.

A CNN/ORC International survey released Friday, meanwhile, indicated Obama holds a four point advantage over Romney in the contest for Ohio's much fought over 18 electoral votes.

The latest Washington Post-ABC News tracking poll also suggested massive outreach efforts by the Obama and Romney campaigns are shaking things up in critical swing states with both sides contacting about 20 percent of all likely voters nationally over the last month.

But overall, the national contest has tipped back to 49 percent for Romney and 48 percent for Obama, the Post reported noting that this was not a significant shift from Thursday's 50 to 47 percent edge for Romney, and a return to the numbers from the previous two days.

With most polls putting Romney in the lead nationally, but surveys in the nine or so swing states giving a narrow advantage for Obama, the Post also raised the possibility of Romney carrying the popular vote, but Obama regaining the presidency with electoral votes.

"I think it's a 50/50 possibility - or more," the influential daily cited Mark McKinnon, who was a political strategist for former president George W. Bush, as saying.

"If the election were held tomorrow, it wouldn't just be a possibility, it would be actual," added William A. Galston, a senior fellow at the Brookings Institution, who also served as a policy adviser to former president Bill Clinton.

That would mark the fifth time in American history - and the second time in a dozen years - that the person who occupies the White House was not the one who got the most votes on Election Day, the Post noted.

In 2000, then Vice President Al Gore won the popular vote by 500,000 votes, but Bush won the presidency after a recount of Florida votes that required a US Supreme Court decision to determine the winner.

But what has never happened before is an incumbent president being returned to office without winning the popular vote, the Post said. Every modern president to be re-elected - Dwight D. Eisenhower, Richard M. Nixon, Ronald Reagan, Clinton, George W. Bush - has gotten a bigger share of the vote in their second bid for office than their first, it noted.