Vice President Kamala Harris and former President Donald Trump head into a presidential debate virtually tied in national polling, raising the stakes for a showdown that could prove pivotal in the 2024 election.

“[The election] is really sitting on a knife’s edge on the electoral college,” Henry Olsen, a senior fellow with the Ethics and Public Policy Center, told The Epoch Times. “One point in either direction is something that could really matter.”

We asked political experts to explain what both candidates must do to perform well in this debate—and what could happen if they don’t.

Here’s what to watch for as Harris and Trump square off at the National Constitution Center in Philadelphia.

Harris

Winning or losing this debate could come down to which candidate does the better job of defining Kamala Harris, which will likely be the goal of both.

“We’ve seen Trump now forever, but we have not seen Kamala Harris as much,” Aaron Dusso, a professor of political science at Indiana University, told The Epoch Times. “So there’s probably a bit more at stake here, where she continues to introduce herself to the country.”

Some 31 percent of voters said they needed to know more about Harris, according to a Sept. 5 poll by the New York Times and Siena College. Of those, 63 percent said they wanted to learn more about Harris’s policies.

“Kamala Harris needs to speak substantively and with some level of detail about policy,” Matthew Wilson, a political science professor at Southern Methodist University, told The Epoch Times. “She’s been very ambiguous about her policy stands and policy goals. And so I think she'll be pushed on that.”

Harris, who had been criticized by the Trump campaign for her lack of policy specifics, published a list of policies on her campaign site over the weekend.

Beyond that, Harris will likely aim to present herself as a person of gravitas, someone who can be trusted with the responsibility of the Oval Office.

“Harris has to come across as presidential—serious, can make hard decisions, can go toe to toe with world leaders,” said Ken Kollman, a professor of politics at the University of Michigan. “It’s a mistake for her to lean into the ‘joy’ emotion in this venue.”

“What she needs to do is convince people that she has the not just temperament but the fortitude to be somebody who is in command,” Olsen said.

Harris spent several days preparing for the debate with advisors in a Pittsburgh hotel, refining two-minute responses to various questions.

Trump

Trump, appearing in his seventh presidential debate, has little need to introduce himself to voters.

“I think what Trump needs to do is begin to define Harris by her record, both as part of the Biden administration, and in what she said and did as a senator,” Olsen said.

That’s exactly what Trump will do, according to his close associates. His goal will be to convince Americans that Harris not only agreed with but was responsible for the policies of the current administration.

“It’s very clear that Kamala Harris is the one who’s been running the country the entire time,” Jason Miller, a senior campaign advisor, told reporters on Sept. 9. “You can’t talk about turning the page when you’re the one who created our current nightmare.”

Rep. Matt Gaetz (R-Fla.) began to lay that groundwork in a call with reporters the day before the debate. “She has a record as a district attorney and as attorney general. That record is dangerously liberal. President Trump is going to tie her to that record during the debate.”

Look for Trump to call Harris to account for the increase in illegal immigration during the past three years, inflation, and the handling of the U.S. withdrawal from Afghanistan.

On the positive side, Trump is likely to describe his administration as a time when the world was relatively free from conflict and Americans enjoyed lower prices for fuel and groceries.

“It would do him a lot of good to project that aura of reassurance and to try to play on voters’ nostalgia for the way things were five years ago,” Wilson said.

Trump, who will be participating in his seventh presidential debate, did not make a major break in his campaign schedule to prepare for this debate but continued to hold rallies.

Danger Points

Biden’s halting debate performance against Trump in June brought increased pressure from party insiders for him to withdraw from the race, which he did a month later.

Our experts said a disastrous result in this debate is unlikely, but a poor performance would hurt either candidate.

For Trump, the biggest mistake would be to become too aggressive, alienating undecided voters by appearing overbearing or self-absorbed.

The former president must avoid giving the impression that he lacks self-control, “which clearly was something that he failed to do in the first debate with Biden in 2020,” Olsen said.

That means not interrupting Harris or appearing domineering, according to Wilson, who said she may try to bait Trump into creating a “viral moment” where he appears overly aggressive.

“He needs to focus less on his personal grievances and more on the ... American people’s grievances,” Dusso said.

For Harris, the danger is going off script and getting lost in policy details or arguments the audience can’t follow.

“There’s one big danger for her, and that’s if she decides to head too far down the path of ‘I need to add one more fact. I’m going to fact-check Donald Trump every time he says something,’” Dusso said.

Given Trump’s unorthodox debating style, trying to keep him in check would be difficult, according to Dusso. “He jumps from one thing to the next, to the next. ... You’ve only got two minutes to respond.”

“She needs to be able to explain herself well,” Olsen said, and not “go into meaningless word salads.”

Both campaigns have attempted to influence opinion ahead of the debate by positioning themselves and their opponent.

“I think he’s gonna lie. He has a playbook he has used in the past,” Harris said in a radio interview aired on Sept. 9.”

Trump predicted that media reports about the debate would skew in Harris’s favor. “You know, if I destroy her in the debate, they'll say Trump suffered a humiliating defeat tonight,” Trump told rally attendees in Mosinee, Wisconsin, on Sept. 7.

Earlier, he had questioned whether he would be treated fairly by the moderators. “A lot depends on ABC. ... I hope they’re going to be fair,” he said in a town hall meeting on Sept. 4.

According to the rules announced by the host network, ABC, there will be no live audience, the candidates will not have access to notes, and there will be no consultations with staff during commercial breaks.

At Stake

The debate is not likely to sway many voters, according to our experts. “The most likely outcome is a draw,” Kollman said. He added that it might affect turnout among key voting groups. Others theorized that a 1- or 2-point swing in the polls could result.

An estimated 5 percent of voters remain undecided in this race, and nearly 10 percent say they are open to changing their minds according to a recent USA/Suffolk poll.

Any impact from the debate likely will not be seen for a few days because most people won’t see the debate itself, according to Dusso. “They hear it accidentally from family, or friends are talking about it, or they’re on Instagram and Twitter or TikTok, and they'll see a clip,” he said.

That could mean the debate’s result could hinge on whoever offers the most memorable “viral moment,” Dusso added.

The 90-minute debate will be aired at 9 p.m. ET, moderated by ABC anchors David Muir of “World News Tonight” Linsey Davis of “Prime.”

Emel Akan and Janice Hisle contributed to this report.