การโต้วาทีครั้งสุดท้ายของผู้สมัครชิงตำแหน่งประธานาธิบดีสหรัฐ

President Barack Obama and Republican presidential nominee Mitt Romney greet one another as moderator Bob Schieffer watches at the start of the third presidential debate at Lynn University, October 22, 2012.

U.S. President Barack Obama and Republican presidential nominee Mitt Romney greet family members following the final U.S. presidential debate in Boca Raton, Florida October 22, 2012.

President Barack Obama greets members of the family of Republican presidential nominee Mitt Romney after the third presidential debate at Lynn University, October 22, 2012, in Boca Raton, Florida.

U.S. President Barack Obama speaks as Republican presidential nominee Mitt Romney listens during the final U.S. presidential debate in Boca Raton, Florida, October 22, 2012.

Richard and Carol Smith look at the broadcast screen showing Republican presidential nominee Mitt Romney and U.S. President Barack Obama during the final U.S. presidential debate in Boca Raton, Florida, October 22, 2012.

President Barack Obama speaks as Republican presidential nominee Mitt Romney and moderator Bob Schieffer listen during the third presidential debate at Lynn University, October 22, 2012, in Boca Raton, Flordia.

The crowd watch Republican presidential nominee Mitt Romney and U.S. President Barack Obama meet in the final U.S. presidential debate in Boca Raton, Florida, October 22, 2012.

Students and professors cheer while dancing with cutouts of President Barack Obama, left, and Republican presidential candidate Mitt Romney, right, prior to watching the third televised presidential debate at Harvard University's John F. Kennedy School of

Freshman Shannon Anderson, 19, sits on the edge of the pool during a party outside the debate hall ahead of the presidential debate between Republican presidential candidate Mitt Romney and President Barack Obama, at Lynn University October 22, 2012, in