The most important question the Biden-Trump debate may answer for voters

President Joe Biden and former President Donald Trump differ on many important issues that will likely provoke intense arguments when they meet for their first debate Thursday, on CNN. Yet more lasting than the substance of any of these confrontations may be the conclusions voters draw from them about each man’s ability to lead the nation over the next four years.

Presidential debates have usually mattered more for revealing the candidates’ character and competence than for illuminating the policy disagreements between them. That may be especially true this year as both Biden and Trump arrive on the Atlanta debate stage facing fundamental questions about their fitness for the job.

Biden is confronting widespread doubts about whether he has the physical and mental capacity to handle the presidency today, much less through a possible second four-year term. Trump’s biggest challenge is character: While retrospective assessments of his presidency have been improving, many voters remain unconvinced he possesses the ethics, commitment to the rule of law or moral compass they expect in a president.

For either man, the debate could assuage or intensify these concerns. A halting or tentative performance from Biden could harden the doubts of voters who consider him too old or weak for the job. In turn, a hectoring or volatile performance from Trump – like the one he delivered in 2020’s first debate between the two men – would reinforce voter concerns that returning the former president to the Oval Office risks perpetual chaos and conflict.

Few subjects divide political practitioners and political scientists more than the importance of presidential debates. Almost without exception, academics who have studied public opinion polls tracing back decades believe that the debates, for all the attention they receive, have had only minimal effect, if any at all, on the outcome of presidential races.

The presidential debates have mattered “at the margin – a little bit here, a little bit there …maybe,” said Christopher Wlezien, a professor of government at the University of Texas at Austin and co-author of “The Timeline of Presidential Elections,” a book about the impact of the campaigns on the outcome of presidential races. “It’s really hard to tell if it’s had much of an effect at all. The best way to predict where we are going to be at the end of the debate season is where we are at the beginning of the debate season.”

People who work on presidential campaigns are much more likely than the political scientists to view the debates as potentially pivotal moments. Political practitioners often point to presidential contests – such as those in 1960, 1980 and 1992 – when the debates solidified attitudes about the candidates that had been developing during the campaign but had not fully formed.

Over the history of presidential debates, these crystallizing moments have rarely revolved around one candidate clearly besting another in an argument about a specific policy. As Wlezien pointed out, each candidate will inevitably seem more comfortable and persuasive than the other on some subjects under discussion. “Think about how many different issues are asked about,” he said. “It’s like a campaign: You could have a good day today, but the other side could have a good day tomorrow. It’s a little like that during the course of a debate.” Since every candidate has typically carried the debate on some subjects, and been forced on the defensive around others, “It’s not clear the sum of all that stuff is going to be very, very influential,” he added.

The most lasting moments in presidential debates have tended to be those that shape voters’ judgments about the personal character and capacity of the candidates. And that usually turns less on detailed arguments about tax policy or foreign affairs than the strength, mastery, energy and empathy that each candidate projects. “You can generally tell who is winning the debate by watching it with the sound off,” said Doug Sosnik, who served as the top White House political adviser in Bill Clinton’s 1996 reelection campaign.

Famously in 1960, the first televised presidential debate, the physical contrast between the crisp and confident John F. Kennedy and the dour and sweaty Richard Nixon visually underscored Kennedy’s core argument that he could provide the nation a needed generational transition and new infusion of energy.

Likewise, when President George H.W. Bush in 1992 checked his watch during a town hall-style debate with challengers Clinton and Ross Perot, it became an instant symbol for Clinton’s case that Bush no longer had the energy or engagement to address the nation’s domestic challenges.

Maybe the most telling example of personal signals eclipsing policy arguments in a debate came in the sole 1980 encounter between President Jimmy Carter and his Republican opponent, Ronald Reagan. Carter, facing deep discontent over his record and the state of the economy, had stayed close in the race by fanning doubts about whether Reagan was too ideologically extreme and too much of a “warmonger” willing to risk nuclear confrontation with the Soviet Union.

At one point in the debate, Carter accurately pointed out that Reagan had started his political career by opposing the creation of Medicare and therefore was unlikely to support the expanded access to health insurance that Carter said Americans needed. Carter touched all the bases political strategists consider essential to winning policy arguments in debates: He linked Reagan’s prior record with a forward-looking contrast on an issue important to voters.

And yet Carter’s gambit utterly backfired when Reagan responded with his famous retort: “There you go again.” In fact, in his answer, Reagan misrepresented his own opposition to Medicare; Carter had that right. But the genial tone and easy confidence of Reagan’s response immediately punctured Carter’s portrayal of him as scary and risky. Reagan at the debate proved “himself neither a war-monger nor a dope,” wrote William Safire, the former Nixon speechwriter-turned-acerbic New York Times columnist. “With that proof, the Carter campaign of fear of Reagan fell apart.”

Political scientists point out that even in these cases, the debates did not reset the campaigns’ trajectory but provided a kind of exclamation point that confirmed underlying trends. Both Carter in 1980 and H.W. Bush in 1992, for instance, faced a dynamic in which most voters were clearly ready to fire them (as measured by their low approval ratings) but were unsure about hiring the alternative. In each case, the debates provided the reassurance voters needed to make the change they were already leaning toward.

The environment around this year’s debates between Biden and Trump shares some similarities to these earlier contests but also differs in ways that could introduce some shifting dynamics.

Lynn Vavreck, a UCLA political scientist and co-author of well-respected books on the 2016 and 2020 presidential races, said that she expects, as with previous debates, this year’s encounters will have at most a modest effect on voters’ preferences. The difference now, she added, is that with the country so closely divided between the parties, even changes in attitudes among very small groups of voters could have a huge impact on the outcome.

“These elections are turning on very few votes in very few states, and what that means is literally anything you could think of could be pivotal,” Vavreck said. “You don’t have to move 5 points. You have to swing 5,000 votes.”

Each side believes the other presents tempting targets on key issues. Republicans are eager to hear Trump prosecute the case against Biden’s presidential record, particularly on inflation and immigration. Democrats see enormous opportunity for Biden to portray Trump as a threat to women’s rights and to democracy more broadly, and to frame the former president’s economic agenda as a giveaway to the wealthy and big corporations.

“A lot of people who are hurting want someone who will shake up the system,” said Adam Green, the co-founder of the Progressive Change Campaign Committee, a liberal group. “That’s why repositioning Trump as in the pocket of billionaires and corporate price gougers … changes the dynamic where he is no longer the change agent – he’s the problem.”

Yet, given how many doubts each candidate faces about his personal qualities, what they say on the stage may be less important than how they say it. In some respects, Trump’s situation is similar to Reagan’s in 1980 and Clinton’s in 1992. As in those races, most voters now consistently say they disapprove of the incumbent’s performance. That means the challenger does not face as big a burden to convince most Americans to remove the incumbent from office. The real question for Trump, as for Reagan and Clinton, is whether he can convince voters already inclined to replace the president that he’s an acceptable alternative.

With that imperative, many strategists in both parties say Trump’s top priority at the debate must be to reassure voters uncertain about his temperament, ethics and stability. “The opportunity here is to demonstrate that he’s not the same old wild and crazy Donald Trump,” said Jason Cabel Roe, former executive director of the Michigan Republican Party. Roe has been a frequent critic of Trump but now believes the former president is favored to win Michigan. “If he comports himself in a more presidential way,” Roe added, “I think he can reap huge windfalls from this debate.”

Of course, with Trump, that’s a huge “if.” His campaign rallies this year have been as raucous and filled with false and inflammatory statements as before. For Trump, repeating the claims that the 2020 election was stolen “will be a trip wire for him because I have yet to see him willing to say that in a way that makes sense to people,” said Roe. Trump faces a similar risk if he repeats his pledges to pardon some of the January 6, 2021, rioters, whom he’s called “warriors” and “victims.”

With Trump’s retrospective job approval improving – largely because voters remember the cost of living as being more affordable during his presidency – one of Biden’s priorities, many Democrats believe, must be to remind voters of all the other aspects of Trump’s tenure that they didn’t like. Trump could make that easier if he delivers a performance like he did in the first 2020 debate, when he interrupted and mocked Biden in a manner that seemed to encapsulate the perpetual confrontation of his presidency. “He was totally unhinged, and I think he may have lost the presidential election in that first debate,” said William Galston, a senior fellow in governance at the Brookings Institution and a former aide in the Clinton White House.

To strategists in both parties, Biden’s greatest need at the debate isn’t hard to identify: As Sosnik put it, he must rebut “the current narrative that he is too old and not up to the job.” Just as Trump’s situation in some respects echoes Reagan’s in the 1980 debate, Biden’s in some ways reprises Reagan’s in the 1984 debates.

Reagan then was 73, at that point the oldest president in American history. While he held a steady lead in polls over Democratic nominee Walter Mondale through the 1984 campaign, Reagan’s halting and unsteady performance at his first debate unleashed a torrent of discussion on whether he was too old for the job – a previously taboo subject. Galston, who was Mondale’s top issue adviser in that 1984 campaign, remembers him coming off the first debate stage and telling his aides, “‘This is what the White House has been hiding from us for the past six months.’ He was really surprised and shaken.”

At the second debate with Mondale, Reagan defused the controversy with another famous turn of phrase. “I will not make age an issue of this campaign,” Reagan insisted. “I am not going to exploit, for political purposes, my opponent’s youth and inexperience.” Onstage Mondale laughed, but Galston said the candidate and the top campaign aides alike recognized that whatever door Reagan had opened in the first debate for Mondale to make the race more competitive, he had slammed it shut with that answer in the second.

Galston believes it won’t be nearly as easy for Biden to dispel the doubts about his age. “Biden’s situation is more difficult; it’s not similar to Reagan because it was one episode [at the first debate] that raised the age issue for Reagan,” Galston said. “In Biden’s case it’s been a steady drumbeat over many months. The negative impression Biden has to overcome is much more deeply entrenched. I can’t imagine a single line doing for Biden what a single line did for Reagan. I think his challenge is to put on a sustained focused performance for 90 minutes.”

The personal and policy points Biden wants to make at the debate could converge. The president’s greatest policy vulnerability is his record on inflation. His main strategy to rebut the Republican attacks over higher prices has been to emphasize ways he is confronting powerful interests to bring down costs – for instance through Medicare negotiating with pharmaceutical companies to lower drug prices — and to portray Trump as beholden to those same interests. As Green argues, more effective for Biden than telling voters how hard he is fighting for them against those interests would be to show them “by fighting Trump. … That projects the vibe of strength.”

Plenty could go wrong at the debate for Trump too. But of the two men, Biden at this point is facing what appear to be more intractable obstacles, with only about two-fifths of Americans consistently saying they approve of his job performance and nearly twice as many indicating they believe he’s too old for the job.

As a result, the range of possible outcomes for Biden at the debate may be wider than for Trump. If Biden delivers an effective performance that eases concerns about his capacity, noted Galston, it “could shake up public perceptions about who he is as a person right now. If it goes really well, I think it could bring the race back to jump ball.”

If the debate goes badly for the president, the Democratic anxiety about renominating Biden, which lessened after the State of the Union, may return to five-alarm levels.

“The stakes for Trump are high,” said Galston, in a view echoed by many strategists in both parties. “The stakes for Biden are much higher.”

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