Images: Past Presidential Debates

Republican Vice President Richard M. Nixon, listens as Sen. John F. Kennedy, the Democratic presidential nominee, makes a point during a live broadcast from a New York television studio of their fourth presidential debate on Oct. 21, 1960. The candidates' performance in this debate is often credited with helping lift Kennedy to victory in the general election. Associated Press

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., Sept. 26, 1960. For the first time in US history a debate between presidential candidates is shown on television. Associated Press

U.S. President Ronald Reagan, left, and his Democratic challenger Walter Mondale, right, are seen during their televised presidential debate, in Kansas City, Mo., October 22, 1984. Seen in the foreground center is debate moderator Edwin Newman. Associated Press

U.S. Vice President George Bush and Mass. Gov. Michael Dukakis gesture during their first presidential debate at Wake Forest University in Winston-Salem, N.C., Sunday, Sept. 25, 1988. The panel and moderator are seated in foreground. Associated Press

Republican presidential candidate Bob Dole watches President Bill Clinton as he answers questions during 2nd presidential debate on Wednesday, Oct. 16, 1996 in San Diego, California. Associated Press

President Bush, left, talks with independent candidate Ross Perot as Democratic candidate Bill Clinton stands aside at the end of their second presidential debate in Richmond, Va., Oct. 15, 1992. Associated Press

President Gerald Ford, right, emphasizes a point during his second debate with Jimmy Carter, left, at Palace of Fine Arts Theater, Oct. 6, 1976, San Francisco, Calif. Associated Press

In tis Oct. 28, 1980 file photo, President Jimmy Carter, left, and Republican presidential candidate Ronald Reagan, shake hands in Cleveland, Ohio, before debating before a nationwide television audience. Associated Press

Democratic presidential candidate Bill Clinton looks on as President George Bush speaks, Oct. 11, 1992 in St. Louis, during the first of three planned debates among the three major candidates. Associated Press

President George Bush, right, answers a question during third and final presidential debate as Gov. Bill Clinton watches in East Lansing, Mich., Oct. 19, 1992. Associated Press

Republican presidential nominee Mitt Romney, left, and President Barack Obama spar during a presidential debate at Hofstra University in Hempstead, N.Y. The first presidential debate in the 2016 race is being held on September 26 at Hofstra, chosen to pinch-hit as an alternate after Wright State University in Ohio dropped out due to concerns over security and costs. Associated Press

President Bush answers a question as his Democratic challenger John Kerry takes notes during the second presidential debate in St. Louis, Friday, Oct. 8, 2004. Associated Press

In this Oct. 21, 1960 file photo, Sen. John F. Kennedy, D-Mass., right, speaks and Vice President Richard M. Nixon listens during the fourth presidential debate from a New York studio. The fall debates are always a big part of any presidential campaign. But with many 2016 voters underwhelmed by both Hillary Clinton and Donald Trump, this year's debates could well be more influential than usual. Associated Press

In this Oct. 28, 1980 file photo, President Jimmy Carter shakes hands with Republican Presidential candidate Ronald Reagan after debating in the Cleveland Music Hall in Cleveland. The fall debates are always a big part of any presidential campaign. But with many 2016 voters underwhelmed by both Hillary Clinton and Donald Trump, this year's debates could well be more influential than usual. In 1980, a cheerful Reagan shone in his debate against Carter, scolding him with a gentle "There you go again," and posing a pointed closing question: "Are you better off than you were four years ago?" Associated Press