Vice President Kamala Harris and Donald Trump will be face-to-face for the first time Tuesday night as they debate, aiming to keep the other out of the Oval Office.

Harris closed the polling gap on Trump after her surprise ascension in July to the Democratic nomination, but she still trails in some polls. She will have a chance to change that when the nominees square off in Philadelphia.

The vice president had narrow leads nationally in a list of polls released in the past few weeks, but her campaign got a surprise Sunday when a New York Times-Siena College survey put Trump up 1 percentage point — suggesting her surge after President Joe Biden dropped out has ended.

But a strong debate performance against Trump could give her White House bid a boost with less than two months until Election Day. The stakes couldn’t be higher in a race that shows ample signs of a photo finish on Nov. 5.

“If her momentum continues, Harris will probably win. But it may not. If she stumbles in the Sept. 10 debate, the momentum of the race may change,” according to William Galston of the Brookings Institution, a former White House aide under President Bill Clinton. “Trump’s campaign could regain its balance and sharpen its focus. And unforeseen events could shift the dynamic between the candidates.”

Polls suggest voters want to hear from Harris about policy, and prognosticators in Las Vegas say she has a better chance of winning the debate. “Latest odds reveal Harris has an implied probability of 57% of winning the debate, while Trump only holds a 53% chance,” according to Vegas Insider. “Kamala Harris’ past debate performance gives her a 55 percent chance of winning the debate, while Donald Trump has a 45 percent shot.”

Here are three things to watch as Harris and Trump debate.

Donald the distracted?

The nominees have taken different paths to Philadelphia, with Harris debate-prepping in Pittsburgh and Trump making public appearances saying and posting more outlandish things — even threatening, if elected, to throw his opponents in jail.

“Therefore, the 2024 Election, where Votes have just started being cast, will be under the closest professional scrutiny and, WHEN I WIN, those people that CHEATED will be prosecuted to the fullest extent of the Law, which will include long term prison sentences so that this Depravity of Justice does not happen again,” Trump wrote in a post on Sunday. “Those involved in unscrupulous behavior will be sought out, caught, and prosecuted at levels, unfortunately, never seen before in our Country.”

That followed a Friday press appearance in New York during which Trump repeatedly insulted several women who have accused him of sexual assault at a time when women voters could decide the election.

The former president’s antics in recent weeks led one Republican pollster to question whether his heart really is in the presidential race.

“I have never seen a candidate more determined to blow an election. Instead of talking about affordability and immigration security (the top public issues), Trump is once again screaming about prosecuting his opponents,” pollster Frank Luntz wrote on X. “Message to Donald: Focus on helping voters, not yourself.”

In a radio interview that aired Monday, Harris said she was ready to deal with a barrage of lies and insults from Trump because the former president “plays from this really old and tired playbook.”

“There’s no floor for him in terms of how low he will go,” Harris said in the interview. “And we should be prepared for that. We should be prepared for the fact that he is not burdened by telling the truth. And we should be prepared for the fact that he is probably going to speak a lot of untruths.”

Abortion access

Harris has been telling supporters at her rallies for more than a month that the election likely will be extremely close and that Democrats have work to do to secure enough votes to put her in the White House.

She and her campaign are banking that legal access to abortion as the issue that will help her with women voters, especially college-educated white suburban women who often vote Republican.

“The impact of abortion on the 2022 midterms, when Democrats did much better than expected, is undeniable. But some evidence suggests that its impact may be more muted in this year’s contest,” Galston noted.

Abortion ranked second, at 15%, in the Times-Siena survey when likely voters were asked what issue was most important to them. The economy was first, at 22%, and immigration third, at 12%.

But, to Galston’s point, abortion ranked eighth when registered voters in seven swing states were asked by polling firm Blueprint about their top issues. Still, more of them said they trusted Harris more on abortion than Trump by an 11-point margin. Notably, among registered independent voters in those battlegrounds, the vice president’s advantage grew to 24 percentage points.

Expect her to try to appeal to more voters in that bloc on Tuesday night.

Debate styles

Harris is generally regarded to be a solid but not spectacular debater, and often uses her experience as a prosecutor to drive an effective narrative.

Pundits are divided over what she needs to achieve in the debate, with some suggesting she should focus on staying above the fray and introducing herself to American voters. Others say she faces a high bar to convince the nation she is ready to become the first Black woman president.

“For her, the best strategy is to stand back and let people see who Trump is,” said Errin Haines, an editor with the 19th, which covers gender issues. “It’s hard to imagine there will not be a moment in which he doesn’t interact with her in a way that has racial or gendered overtones.”

Trump can throw debate opponents off their game with aggressive and unpredictable attacks, although he was noticeably more restrained in his debate with Biden, whose poor performance eventually forced him to drop out of the race.

“The difficulty debating Trump is that he doesn’t really debate in any conventional sense,” said David Niven, a University of Cincinnati political science and former speechwriter. “He doesn’t lay out facts. He doesn’t engage in the ideas of his opponent. He just barrels through.

Crossover alliances

It’s doubtful anyone had this on their election-year bingo card: A Democratic presidential nominee praising Iraq War architect and staunch conservative former Vice President Dick Cheney. In any other year, that might seem laughable.

But bringing up Cheney could give Trump, who has struggled to settle on an anti-Harris message, a much-needed line of attack.

Cheney has long been a proponent of using U.S. military force, even starting preemptive wars. Trump is unabashedly anti-war, often calling them “stupid” and even appearing, at times, to harshly judge those who have made the ultimate sacrifice.

“Well, he’s clearly the old guard, the guard that, you know, the country club Republicans that don’t support Donald Trump,” Corey Lewandowski, a Trump campaign adviser, said Sunday about Cheney on Fox News.

This report contains information from the New York Daily News.