Washington, DC – On one side of the stage will be the prosecutor, seeking to dismiss her opponent as a danger to democracy and a vestige of the past.

And on the other will be the real estate magnate, blasting his rival as an ultra-liberal politician who will regulate the economy into stagnation.

Tuesday’s presidential debate will be the first opportunity for Vice President Kamala Harris and former President Donald Trump to meet face-to-face as they spar over the future of the United States.

And the two candidates have been sharpening their attacks and plotting a strategy to pull ahead in their neck-and-neck race.

The televised debate, hosted by ABC News, may well turn out to be the only opportunity for Harris and Trump to confront one another in person before the November 5 election.

And that means the stakes are high. Aaron Kall, a professor at the University of Michigan, studies presidential debates and warns not to dismiss their importance.

“They can’t win you an election, but certainly they can lose it,” Kall said.

The shadow of June’s debate

The showdown in Philadelphia, Pennsylvania, is the second presidential debate this election cycle.

But experts said the casualties of the first debate should serve as a warning for the participants this time around.

The first debate took place on June 27, and it was the lightning rod that took down President Joe Biden’s re-election campaign.

The presumptive Democratic candidate at the time, Biden faltered as he faced Trump on the debate stage, trailing off mid-sentence and failing to articulate basic talking points.

His feeble performance led to a crescendo of concerns over the 81-year-old’s age and ability.

Less than a month later, Biden had dropped out of the race, and Harris soon replaced him as the Democratic nominee.

But experts say the events of the transformative June debate will loom large as Harris and her Republican rival Trump craft their strategies for Tuesday. Some predict Biden’s bellyflop may even bring more eyeballs to Tuesday’s debate.

“The Biden and Trump debate, you can say in a declarative sentence, was the most consequential presidential debate in American history,” Barbara Perry, a presidential historian at the University of Virginia, told Al Jazeera. “So it shows the stakes are real and high.”

Kall, meanwhile, pointed to the June debate as evidence that a high-profile blunder can cost a candidate the election.

“In a 90-minute debate, you can make a mistake or gaffe or do something that brands you going forward — like Biden not having the stamina to do another four years,” he said.

Harris’s strategy

Both the Harris and Trump campaigns have been mum about the tactics they plan to use for Tuesday’s debate. After all, airing their strategies in public could blunt their efficacy.

But Harris’s team appears to be hoping to give Trump a runway to crash his own plane.

Her campaign unsuccessfully called for Trump’s microphone to be unmuted between questions, to allow him to speak out of turn.

That was a reversal of what Biden’s campaign had pushed for in June. Biden’s team had hoped a muted microphone would stymy the outburst-prone Trump, particularly with no audience in attendance.

Instead, “it backfired”, according to Kall. He believes the silence gave Trump a more staid appearance, one that emphasised Biden’s stumbles.

Harris’s team appeared to be hoping for a repeat of an earlier Trump and Biden debate, in Cleveland in 2020, when Trump made numerous interjections that read as chaotic. In turn, Biden was seen to come out on top.

However, the Harris campaign’s request to keep Trump’s microphone unmuted was ultimately denied.

Matthew Levendusky, a political science professor at the University of Pennsylvania, said another Harris priority will be to use the debate stage to establish herself with the US public.

Harris only launched her presidential campaign seven weeks ago. She has therefore had far less time in the national spotlight than Trump.

But critics point to her past debate performances as a positive sign going into Tuesday’s event.

During the 2020 election cycle, for instance, Harris took part in Democratic presidential primary debates, and she generated buzz for landing successful punches on her future boss Biden.

She also excelled in a policy-heavy vice presidential debate against Mike Pence during the general election that same year.

Harris — the former district attorney of San Francisco and attorney general of California — has a prosecutorial style, something she exercised during her time in the Senate. Her hard-knuckle questions during Senate committee hearings gained her a national profile.

Levendusky said Harris will aim to reprise that role on Tuesday’s debate stage. She will be “looking to come off as tough and grill Trump and show that she can rebut him”, he told Al Jazeera.

“But of course, the danger for her is that, as a woman of colour, she’s in a tough position given race and gender stereotypes about appropriate behaviour,” Levendusky added. “So far, she seems to be very effectively managing that tightrope, and this is her chance to highlight these skills on an even larger stage.”

Trump’s ‘sixth sense’

Trump, meanwhile, will be making his seventh appearance in a general election debate — more than any candidate in US history.

He continues to be powered by one entrenched factor, according to Perry: He seems impervious to the standards applied to other candidates and their behaviour. His base will support him no matter what.

“Whatever rules there were have become immaterial to him,” Perry said. “He can’t be pinned down, and he can’t be countered, because it doesn’t matter to the people who are locked into voting for him.”

But experts like Perry warn that Trump needs to expand his appeal beyond his base in order to win the election this November.

Perry pointed out that Trump only won the presidency in 2016 thanks to the Electoral College, a system of weighted voting where “electors” are awarded based on state election results. The candidate who wins the most votes in a given state often wins all of that state’s electors.

In both 2016 and 2020, however, Trump lost the national popular vote — earning fewer votes overall than his Democratic rivals in each case.

That means Trump still needs to attract voters outside of his staunchest base to ensure victory, according to Perry.

On the debate stage, Trump — a former reality TV star — excels at being a “moving target”, according to Kall. The Republican has a knack for traipsing through tangents and launching non-sequitur attacks that can be confounding to opponents.

Kall pointed out that Trump’s unpredictable debate performances in 2016 proved to be jet fuel for his meteoric rise in politics.

And Trump continues to show uncanny instincts when it comes to capitalising on camera-ready, politically significant moments, as evidenced by his defiant fist pump following an assassination attempt in July, Kall said.

“He made sure the image that was captured was most politically advantageous to him,” Kall explained. “It’s the same in debates. He has a spidery sixth sense of knowing when there is a key exchange or moment in a debate that everyone’s going to be talking about and could potentially go viral.”

Differences in preparation

The lead-up to the debate has also offered an indication of how each candidate may react on the debate stage.

Their preparation methods reveal a counterpoint in style. Trump has continued to eschew traditional debate preparation for more free-wheeling policy discussions with staffers, according to media reports.

But Harris has stationed herself in Pennsylvania to practice with mock debates, using a Trump stand-in just as Biden had in the past.

Nevertheless, Trump has reportedly tapped Tulsi Gabbard, a former Democratic congresswoman, to help with his debate preparation. Critics say Gabbard showed a unique ability to shake Harris on the debate stage during the 2020 Democratic primaries.

At 78, Trump’s advanced age could also be a liability as he faces the 59-year-old Harris. It will be the first time he has publicly grappled with a considerably younger debate opponent in years.

Levendusky pointed out that Trump’s blustery, unrehearsed style has been a double-edged sword — one that could alienate viewers as much as attract them.

“For Trump, he wants to do something to disrupt the narrative and take back control of the news cycle,” Levendusky explained. “But his risk is that he falls into his traditional pattern and that reminds voters of what they disliked about him.”

‘Stereotypical tropes’

The experts who spoke to Al Jazeera also warned that Trump’s approach to his rival’s gender and race could also prove divisive during the debate.

Harris is only the second woman ever to lead a major party’s presidential ticket after Democrat Hillary Clinton faced Trump in 2016. She is also the first Black woman and South Asian woman to lead the party.

On the debate stage, Harris will deal with societal preconceptions that Trump does not have to contend with, according to Kelly Dittmar, the director of research at the Center for American Women and Politics at Rutgers University-Camden.

“Harris, I’m sure, is being advised in relation to things like tone and showing emotion and reaction to Trump’s types of goading,” Dittmar told Al Jazeera.

“Because women are more often subjected to claims that they’re overly emotional. There are stereotypical tropes of Black women being angry that she is surely aware of, and you can see evidence in the way that she, very calmly, often in these types of settings, responds.”

Trump, meanwhile, has leaned into sexist attacks throughout his political career, repeatedly labelling Clinton a “nasty woman” and looming behind her during a debate in 2016.

He also infamously said that Fox News moderator Megyn Kelly had “blood coming out of her wherever” following a Republican primary debate.

Dittmar noted that Trump has continued that line of attack with Harris, using gender-coded insults. He has, for example, called Harris  “incompetent”, ridiculed her laugh and commented on her physical appearance.

Whether he continues to do so on the debate stage will be an indicator of which audience he seeks to rally.

“Leaning into the hyper-masculinity, the more aggressive approach that he has taken in previous debates, that’s going to land better among his existing base,” Dittmar explained.

“On the flip side, if he is trying to engage and gain back any support from voters who are — quote, unquote — in the middle, you would see him strategically try to emphasise policy differences over that personal kind of rhetoric.”

“Although it’s unclear if he can stick to that,” Dittmar added.

The challenge for Harris, Dittmar said, is to remain unflappable when faced with Trump’s remarks. But she believes Harris has already shown her steady stage presence through her time as a prosecutor and in the Senate.

Maintaining that same level-headed persona during the debate could boost Harris’s chances in the November race.

“People typically look for leaders who can be unrattled by these high-pressure moments,” Dittmar said. “That is somewhere that we already know Harris excels and can it translate into a perception that she is presidential.”