Forty years ago, U.S. president Gerald Ford took a pretty straightforward question on U.S.-Soviet relations from a New York Times reporter during a televised presidential debate and batted back a clumsy and confusing reply.
"There is no Soviet domination of Eastern Europe and there never will be under a Ford administration," said Mr. Ford, as the Democratic presidential candidate, Jimmy Carter, looked on.
The Ford comment confounded the questioner and other observers and was quickly labelled as a gaffe that became the focus of follow-up stories after the debate and widely seen by pundits as a turning point.
What he meant to say is that regardless of the Soviet sphere of influence and occupation in Eastern Europe, the people in that region did not see themselves as being conquered, crushed or forgotten.
His answer would turn out to be a much-discussed moment in presidential debate history: Was it a gaffe? Did it cost him the election? As Hillary Clinton and Donald Trump face off in the presidential debates beginning Sept. 26, it's worth testing the idea that U.S. presidential debates sway elections.
"The reality is most people have made up their minds before they view the debates and so the value of debates is confirming an already made decision, not creating a new decision," said Kathleen Hall Jamieson, professor of communication and director of the Annenberg Public Policy Center at University of Pennsylvania, who studies presidential debates and how they impact elections.
But debates can matter in tight presidential races, she added.
John F. Kennedy won the 1960 election by the slimmest of margins, or about 100,000 votes. In the first-ever televised debate in history, a tanned and telegenic Mr. Kennedy exuded confidence and youth, while his opponent sweated and appeared uncomfortable under the studio lights.
Ted Sorensen, Mr. Kennedy's speechwriter and debate coach, later recalled that his boss's strong performance won over Democrats who thought he was too young to be president and among independents who got their first look at the candidate.
"Kennedy did not 'clinch' the election on debate night, as [legendary CBS news producer] Don Hewitt, who directed the broadcast, later maintained. On Election Day, however, in a closely contested popular vote, Kennedy's performance made all the difference," he wrote in The New York Times in 2010, on the 50 th anniversary of the debate.
The 2000 presidential election and the debates between George W. Bush and Al Gore are instructive for how the post-debate framing can shape the views of voters.
Mr. Gore lost the first debate largely in the hours after debating his rival.
"Within 18 hours, they had turned perception around to where the entire story was about me sighing. And that's scary. That's scary," Mr. Gore later recounted in a 2007 Vanity Fair interview.
Bush campaign spin and mainstream media attention on Mr. Gore's minor debate-stage inaccuracies and sighing caught on microphone when Mr. Bush was speaking became the focus of post-debate coverage.
The coverage fed in to the narrative that Mr. Gore was untrustworthy, explains Prof. Jamieson.
"The public didn't hear those things as remotely problematic, just as the public did not see Ford's statement on Eastern Europe in 1976 as problematic. Once they heard the press commentary saying it was problematic, the public adopted the press view of the debate," she said.
That proved particularly harmful in Mr. Ford's case.
"If he hadn't stalled in the polls he might have won that election because he was closing in the polls, he was moving up. What if he had continued that trajectory? He would have won," said Prof. Jamieson.
"So that's a possible instance in which something that happened in the debate, as interpreted by the press, may have affected the outcome by hurting Ford," she added.