President Obama greets the crowd as he takes the stage at a campaign event at the Delray Beach Tennis Center on Tuesday, Oct. 23, 2012, in Delray Beach, Fla., a day after the final presidential debate against Republican nominee Mitt Romney. (AP Photo/Pablo Martinez Monsivais)
Republican presidential nominee Mitt Romney and President Barack Obama react to moderator Bob Schieffer during the third presidential debate at Lynn University, Monday, Oct. 22, 2012, in Boca Raton, Fla. (AP Photo/Charlie Neibergall)
Moderator Bob Schieffer, center, watches as Republican presidential nominee Mitt Romney, left and President Barack Obama wave to members of the audience during the third presidential debate at Lynn University, Monday, Oct. 22, 2012, in Boca Raton, Fla. (AP Photo/Eric Gay)
President Barack Obama and moderator Bob Schieffer, right, listen to Republican presidential nominee Mitt Romney, left, during the third presidential debate at Lynn University, Monday, Oct. 22, 2012, in Boca Raton, Fla. (AP Photo/David Goldman)
Republican presidential nominee Mitt Romney answers a question during the third presidential debate with President Barack Obama at Lynn University. (AP Photo/Eric Gay)
President Barack Obama listens as Republican presidential nominee Mitt Romney speaks during the third presidential debate at Lynn University. (AP Photo/Pool-Rick Wilking)
Moderator Bob Schieffer addresses the audience before the third presidential debate between President Barack Obama and Republican presidential nominee Mitt Romney. (AP Photo/Eric Gay)
President Barack Obama answers a question as Republican presidential nominee Mitt Romney listens during the third presidential debate. (AP Photo/Pool, Win McNamee)
Republican presidential nominee Mitt Romney and President Barack Obama answer a question during the third presidential debate at Lynn University. (AP Photo/Pool-Win McNamee)
Republican presidential candidate, former Massachusetts Gov. Mitt Romney waves to members of the audience before the start of the last debate. (AP Photo/Pablo Martinez Monsivais)
Moderator Bob Schieffer, center, watches as Republican presidential candidate, former Massachusetts Gov. Mitt Romney and President Barack Obama take their seats before the start of the last debate. (AP Photo/Pablo Martinez Monsivais)
Ann Romney, center, wife of Republican presidential nominee Mitt Romney, watches activity before the start of the third presidential debate at Lynn University. (AP Photo/Pool-Michael Reynolds)