Editor's Note: Thomas Balcerski teaches history at Eastern Connecticut State University. He is the author of "Bosom Friends: The Intimate World of James Buchanan and William Rufus King" (Oxford University Press). He tweets @tbalcerski. The opinions expressed in this commentary are his own. View more opinion at CNN.
(CNN) - The upcoming presidential debates promise to be a watershed moment in this election. Democratic challenger Joe Biden has been preparing to debate sitting Republican President Donald Trump. By contrast, according to NBC News, the President has reportedly eschewed formal preparation, arguing that debate "isn't something you have to practice."
That may be so. But since presidential candidates began appearing on televised debates in 1960, incumbents who don't properly prepare have a decidedly mixed record in the November elections. At the same time, presidential challengers who come out swinging need to be sure they don't miss their mark -- or else face political implosion.
Conventional wisdom is that prior preparation prevents poor performance. Yet the history of presidential debates reminds us that other factors, such as a winning personality and the ability to think on your feet, matter equally, if not more. With the whole world watching, presidential debates are equal parts landing jabs and taking punishment, as much as sticking to the script and exploiting opportunities to score points.
No magic formula exists to predict their outcome, but one thing seems clear in retrospect: just one dramatic exchange can change public perception of the debates, and by extension, the result of the presidential election.
Looking back on the history of presidential debates, these four contests may give us a preview of what's to come:
1976: Gerald Ford vs. Jimmy Carter
The election of 1976 brought the return of the presidential debate, since both Lyndon B. Johnson and Richard Nixon had previously refused them. Gerald Ford was eager to secure a term as president in his own right (following Nixon's resignation post-Watergate), and his team of advisers spent weeks preparing their candidate, including by running him through an exhaustive "murder board." By contrast, an overly confident Carter bombed his first answer on how he would end the ongoing economic recession, when he failed to provide a clear plan of action.
The focus of the second debate turned to foreign policy, an area where Ford was expected to shine. Thirty minutes into the evening, however, Max Frankel of the New York Times asked Ford about the Soviet influence in Eastern Europe (an area Churchill described in 1946 as being behind an "iron curtain"). Incredibly, Ford answered: "there is no Soviet domination of Eastern Europe and there never will be under a Ford administration." All that preparation for nothing.
When given a chance to clarify, Ford refused. Carter seized the opportunity to underline Ford's error: "I would like to see Mr. Ford convince the Polish-Americans and the Czech-Americans and the Hungarian-Americans in this country that those countries don't live under the domination and supervision of the Soviet Union." Advantage Carter.
Following the second debate, Carter enjoyed a 4-point bump in the polls. Even as the race narrowed, Ford could not bring home electoral victory that November.
1984: Ronald Reagan vs. Walter Mondale
In 1984, the Democrats turned to a beloved former vice president to take on an entrenched Republican incumbent. Sound familiar? Back then, it was Walter Mondale challenging Ronald Reagan, and like Biden, Mondale needed to formulate an effective strategy to debate his charismatic opponent. It would not be an easy task. During the 1980 presidential debates, Reagan had effectively negated Carter's attack on Reagan's previous opposition to Medicare with a one-liner that resonates across American history: "There you go again."
With the roles now reversed, Mondale came out strong in the first debate, firing against Reagan's record as president. "You can't wish it away," Mondale charged, in reference to the country's large deficit. Caught flat-footed, even Reagan admitted that he had "flopped."
But in the second debate, Reagan rebounded and delivered yet another of the most memorable lines in American political history. When asked about age as factor in the election (he was 73), Reagan replied: "I am not going to exploit, for political purposes, my opponent's youth and inexperience." The audience erupted into laughter, and even Mondale, in his mid-50s at the time, couldn't help himself from doing the same.
Mondale simply could not make his criticisms of Reagan stick during the debates. Reagan, already comfortably ahead in the polls, cruised to a landslide in November.
1992: George H.W. Bush vs. Bill Clinton vs. Ross Perot
With three major candidates, the 1992 election attracted widespread popular interest. Both Bill Clinton, the charismatic Democratic governor of Arkansas, and independent candidate Ross Perot, a Texas billionaire, looked to unseat Republican incumbent George H.W. Bush.
The first debate went predictably enough, with the three candidates cordially answering questions from the moderators. But, in the second debate, with its new "town hall" format, Bush self-destructed on stage. As audience members asked questions, the President appeared to look at his watch at several points, giving the air of being bored or perhaps uninterested (Bush later said that he was thinking, "Only 10 more minutes of this crap.")
When asked a question about the national debt, Bush waffled. By contrast, Clinton hit a home run, replying compassionately in what has been described as an "I feel your pain" moment. "Well, I've been governor of a small state for 12 years," Clinton said, "I'll tell you how it's affected me ... When a factory closes, I know the people who ran it. When the businesses go bankrupt, I know them."
With his emotional style, Clinton had won the battle for the public's heart. In comparison, Bush's poor performance in the debates foreshadowed his loss at the polls.
2012: Barack Obama vs. Mitt Romney
The election of 2012 demonstrated the continued vulnerability of a sitting president to a challenger's attack. Building up to the debates, Republican challenger Mitt Romney scored points on President Barack Obama's "you didn't build that" line in connection to small business owners. National polls showed the race to be nearly tied leading into the fall.
During the first debate, Obama appeared underprepared and overconfident, even contemptuous, and pundits awarded the contest to Romney.
But at the second debate, Romney fell victim to unforced errors of his own. Speaking about the terrorist attack on the US mission in Benghazi, Romney went on a veritable tirade that spiraled into near incomprehension. Obama coolly remarked: "Please proceed, governor." Later in the debate, Romney again goofed when he declared that his staff had brought him "binders full of women" to work for him as governor of Massachusetts.
On election night, Obama's reelection rankled incredulous conservatives (George W. Bush's former campaign adviser Karl Rove's Fox News meltdown is legendary), but they should not have been surprised. Romney's lackluster performance at the presidential debates pointed to the November outcome.
Presidential debates are won and lost on a mixture of preparation, personality and performance. While preparation can help a lot and personality can save the day, a candidate's performance ultimately matters most. May the best debater win.