A Look Back at Memorable Presidential Debate Moments

When President Biden and former President Donald J. Trump take the debate stage on Thursday, each will be on guard against a gaffe or looking to deliver a one-liner that could dominate the news.

Such presidential debate moments — missteps, one-liners, flops and various “Oops” moments — can even land in the history books.

In the first televised presidential debate, in 1960, a confident Senator John F. Kennedy dominated Vice President Richard Nixon, who appeared sweaty and disheveled as he recovered from an illness. In 1992, President George H.W. Bush impatiently checked his watch in full view of the cameras. President Ronald Reagan — in a move relevant to both candidates this cycle — used a joke to deflate concerns about his age in 1984.

Here is a look back at debate moments that helped define presidential campaigns.

Gov. Ronald Reagan of California, a Republican, faced President Jimmy Carter, a Democrat, in the last debate of 1980, one week before Election Day.

Mr. Carter went on the offensive in a lengthy speech attacking Mr. Reagan’s opposition to Medicare.Mr. Reagan responded with the now-famous line: “There you go again.” The charismatic retort instantly defused Mr. Carter’s protracted attack. Reporters characterized Mr. Carter’s speech as hyperbolic, even though the criticisms were based on Mr. Reagan’s record as governor.