Obama and Romney have scores of election lawyers on hand, ready to jump into action should the need arise. Experts say it's most likely that litigation over the presidency would come down to Florida or Ohio, the states where Romney and Obama have campaigned the hardest.
—A 269-269 Electoral College tie
It takes 270 electoral votes to win. But what if both candidates win 269?
It's never happened. If it did, the newly elected House of Representatives would pick the president. Republicans control the House now, and are likely to hold on to their majority after Election Day. What's more, instead of all 435 members getting a vote, each state delegation would get one vote. Since Republicans control many of the smaller states with fewer representatives, the GOP would have the advantage in this scenario.
But the Senate would get to pick the vice president. The Senate is in Democratic control and probably will stay that way. So would Senate Democrats send Joe Biden to be Romney's vice president? Would Biden accept?
It's safe to assume both candidates are hoping we'll never have to find out.