Four U.S. presidents have assumed office despite losing the popular vote, including Bush and John Quincy Adams, who in 1824 lost both the popular and electoral vote but was handed the election by the House.
All of those elections involved non-incumbents seeking their first term. For a sitting president to lose the popular vote and yet remain the world's most powerful leader would be uncharted territory, raising difficult questions about our electoral system.
A look at the map makes it easy to see exactly how it could happen. Passions run high this year among out-of-power Republicans, and turnout for Romney probably will be big — especially in Southern states that he's likely to win anyway. But last-minute polls show Obama clinging to a small advantage in a handful of battleground states like Ohio and Florida, which could enable him to block Romney's path to the requisite 270 electoral votes.
"This is going to be a turnout election," Obama said Monday in a radio interview. "We've got the votes to win Florida. It just depends on whether people turn out or not."
If Obama marches to 270 but loses the popular vote, he would face the unpleasant prospect of spending four years as a lame duck — or worse. "Republicans would have a pretty strong hand to play against him," said Craig Robinson, the Iowa GOP's former political director.
Image: President Barack Obama calls Wisconsin volunteers as he visits a campaign office call center the morning of the 2012 election, Tuesday, Nov. 6, 2012, in Chicago.