Most polls suggest GOP nominee Mitt Romney is in the lead nationally, but surveys in the nine or so swing states are registering a narrow advantage for President Obama.

What if Romney carries the popular vote, but Obama regains the presidency by winning 270 votes or more in the Electoral College? “I think it’s a 50/50 possibility — or more,” said Mark McKinnon, who was a political strategist for former president George W. Bush.

“If the election were held tomorrow, it wouldn’t just be a possibility, it would be actual,” said William A. Galston.

Galston, a senior fellow at the Brookings Institution, served as a policy adviser to former President Bill Clinton.

That kind of split decision between the electorate and the Electoral College would mark the fifth time in U.S. history — and the second time in a dozen years — that the person who occupied the White House was not the one who got the most votes on Election Day.