President Barack Obama (R) shakes hands with Republican presidential candidate Mitt Romney after the debate. (Photo by Mark Wilson/Getty Images)

 U.S. President Barack Obama (L) shakes hands with Republican presidential candidate Mitt Romney after the debate at Lynn University. (Photo by Michael Reynolds-Pool/Getty Images)

In this handout image provided by The White House, Vice President Joe Biden and his daughter Ashley Biden watch the third presidential debate on October 22, 2012 from a hotel room in Toledo, Ohio. (Photo by David Lienemann/The White House via Getty Images)

President Barack Obama (R) debates with Republican presidential candidate Mitt Romney as moderator Bob Schieffer (C) of CBS looks on at Lynn University. (Photo by Joe Raedle/Getty Images)

President Barack Obama (L) debates with Republican presidential candidate Mitt Romney as moderator Bob Schieffer (C) of CBS looks on. (Photo by Michael Reynolds-Pool/Getty Images)

President Barack Obama (R) debates with Republican presidential candidate Mitt Romney at Lynn University in Boca Raton, Florida.(Photo by Rick Wilking-Pool/Getty Images)

Republican presidential candidate Mitt Romney speaks during a debate with U.S. President Barack Obama at Lynn University in Boca Raton, Florida. (Photo by Mark Wilson/Getty Images)

President Barack Obama (R) debates with Republican presidential candidate Mitt Romney as moderator Bob Schieffer (C) of CBS looks on at Lynn University. (Photo by Joe Raedle/Getty Images)

President Barack Obama debates with Republican presidential candidate Mitt Romney (not seen) at Lynn University on October 22, 2012 in Boca Raton, Florida.(Photo by Mark Wilson/Getty Images)

Republican presidential candidate Mitt Romney listens as moderator Bob Schieffer of CBS speaks during the debate with U.S. President Barack Obama at at Lynn University. (Photo by Marc Serota/Getty Images)

Moderator Bob Schieffer of CBS speaks on stage prior to the debate between U.S. President Barack Obama and Republican presidential candidate Mitt Romney. (Photo by Joe Raedle/Getty Images)

Republican presidential candidate Mitt Romney (R) sits backstage with his wife Ann Romney before the start of a debate with U.S. President Barack Obama at Lynn University on October 22, 2012 in Boca Raton, Florida.(Photo by Justin Sullivan/Getty Images)

A general view outside prior to the debate between U.S. President Barack Obama and Republican presidential candidate Mitt Romney at Lynn University in Boca Raton, Florida. (Photo by Joe Raedle/Getty Images)

First lady Michelle Obama and Robert Wexler attend the debate between U.S. President Barack Obama and Republican presidential candidate Mitt Romney. Photo by Marc Serota/Getty Images)

President Barack Obama (C) greets Republican presidential candidate Mitt Romney (L) as moderator Bob Schieffer of CBS looks on prior to their debate at Lynn University in Boca Raton, Florida. (Photo by Joe Raedle/Getty Images)

Moderator Bob Schieffer of CBS appears on stage prior to the debate between U.S. President Barack Obama and Republican presidential candidate Mitt Romney. (Photo by Michael Reynolds-Pool/Getty Images)