5 / 7

Richard Nixon

FILE - In this Sept. 26, 1960, file photo U.S. Republican presidential candidate Vice President Richard M. Nixon wipes his face with a handkerchief during the nationally televised first of four presidential debates with Sen. John F. Kennedy, Democratic nominee, in Chicago, Ill., for the first televised debate between presidential candidates in U.S. history. Nixon's profuse sweating on stage with cool-as-a-cucumber rival John Kennedy (not shown) in 1960 proved to be stiff competition in the pantheon of campaign misfires. (AP Photo/File)

Great debate moments

By Claudine Zap

The first debate between Republican presidential candidate Mitt Romney and President Barack Obama will be held on Wednesday. While the candidates prepare their talking points, we look back at some of the more memorable moments from past presidential face-offs. A zippy zinger can get serious airplay even after the actual debate is over, but so can an ill-timed gaffe. Here, some of the top moments.