Can Harris prosecute the political case against Trump? Key questions ahead of their debate

NEW YORK -- NEW YORK (AP) — Donald Trump and Kamala Harris will debate for the first — and perhaps, last — time on Tuesday night as the presidential candidates fight to sway voters on the biggest stage in U.S. politics.

The meeting comes just 75 days after President Joe Biden's disastrous debate performance triggered a political earthquake that ultimately forced him from the race. Few expect such a transformative result this time, but Trump is on a mission to end Harris' “honeymoon” as polls suggest the Democratic vice president is now even — or slightly ahead — of the Republican former president in some swing states.

Harris, a former courtroom prosecutor, will enter the night with relatively high expectations against a Republican opponent with 34 felony convictions and a penchant for false statements. The question is whether Harris, who did not particularly stand out during primary debates in her 2020 presidential campaign, can prosecute Trump's glaring liabilities in a face-to-face meeting on live television with the world watching.

The 90-minute meeting begins at 9 p.m. ET Tuesday inside Philadelphia's National Constitutional Center. It will be moderated by ABC News anchors David Muir and Linsey Davis. In accordance with rules negotiated by both campaigns, there will be no live audience.

Here’s what we’re watching for on a historic night:

Can Harris do what Biden could not?

Biden set an incredibly low bar for Harris in the June 27 debate. The president struggled to offer coherent arguments or even finish his sentences. But the anti-Trump coalition was most disappointed that he failed to take advantage of Trump's obvious political liabilities — whether on abortion, the Jan. 6 Capitol attack, character issues or his legal trouble.

Harris is expected to do much better. But even with such fertile terrain, scoring points against Trump on the debate stage is easier said than done. Trump may be the most experienced debater in modern presidential history. As a former reality television star, he knows how to dominate television coverage. And he clearly likes to fight.

Harris recently suggested that she may be looking forward to a political brawl. “Donald,” she told a cheering audience last month in Atlanta, “if you've got something to say, say it to my face.”

Can she back up the tough talk? The world is about to find out.

Can Trump focus?

Trump is not known for his discipline or preparation. His debate performances, like his governing style, are typically fueled much more by instinct than thoughtful analysis.

Therefore, few expect Trump to offer a clear and concise line of attack against Harris on Tuesday night. Still, he needs to do better than the kitchen-sink approach he's been testing on the campaign trail for much of the last month.

Trump has questioned Harris' racial identity. He's falsely called her a communist. He's questioned her strength. He's jabbed her as a San Francisco liberal. And he's reminded voters that she has served in the Biden White House for nearly four years and would presumably continue the president's policies for another four years if she wins.

It is the Biden connection that many Republicans, inside and outside of Trump's campaign, believe is most effective. They want him to evoke Ronald Reagan's 1980 debate-stage jab — “Are you better off?” — early and often.

The question is whether Trump can deliver that message in a way that isn't immediately overshadowed by a much more controversial statement. Recent history offers reasons to be skeptical.

Body language matters

There will, of course, be an obvious gender dynamic on stage Tuesday night.

Fair or not, body language and tone are viewed differently in a debate between a man and a woman. Just ask Hillary Clinton. She said Trump made her “skin crawl” when he stood behind her as she was speaking during a town hall-style debate in 2016.

The candidates will be expected to stay behind their podiums on Tuesday night. But Republicans are hopeful that Trump will avoid any other provocations like pointing, yelling or otherwise approaching Harris in a way that might be off-putting to suburban women or other swing voters.

Harris, too, will face unique challenges related to her race and gender as voters consider whether to make her the nation's first female president. Some voters still say they're not comfortable with the idea. If she comes across as angry, she risks playing into racist tropes about Black women.

While the gender dynamic looms, do not underestimate the significance of their age difference, either.

Harris is almost two decades younger than the 78-year-old Trump. Age was viewed as a political advantage for Trump when he was facing the 81-year-old Biden, but the situation is now reversed against the 59-year-old Harris. If he wins, Trump would be the oldest U.S. president ever elected.

The format will be somewhat different as well, in accordance with a set of rules the candidates agreed upon this week.

There will be no live audience, no opening statements and no props allowed. Candidates’ microphones will be muted when their opponent is on the clock, a stipulation that created some controversy in recent days.

Trump reluctantly agreed to the mute function when he faced Biden in June, but after that debate, his team determined it was a net positive if voters did not hear from the Republican former president while his opponent was speaking. Harris' team was pushing to return to a normal format without mute buttons.

Abortion vs Immigration

Policy sometimes plays second to personality in presidential debates, but there are dramatic differences between the candidates on key issues that are on the minds of millions of voters.

Republicans hope Trump makes immigration a defining issue of the debate.

The GOP has effectively condemned the Biden administration's handling of illegal immigration at the U.S.-Mexico border for much of the last four years. Once an issue that appealed mostly to the Republican base, illegal immigration — and related concerns about drugs, crime and national security — is now a top issue for voters across the political spectrum.

Harris will be eager to remind voters that Trump helped kill a bipartisan immigration bill that would have done much to fix the problem. But overall, Harris is likely to be on the defensive when the issue comes up.

Democrats, meanwhile, want to focus on abortion.

Trump, of course, appointed three Supreme Court justices who later overturned the landmark Roe v. Wade decision that protected a woman's right to choose abortion. Trump has repeatedly said he was proud that Roe was defeated. But aware that such a view isn't popular among many women, he has tried to moderate his stance on the divisive issue.

Harris won't make that easy. Stating the obvious, as a woman, she is positioned to be a much more effective messenger on the issue than Biden was. And Trump can't afford to lose many more female voters.

Look out for wild card Trump

If you ask Trump's previous debate opponents what they're watching for on Tuesday night — and we did — many say the same thing: Look out for the thing he says or does that Harris can't possibly prepare for.

Trump is the ultimate wild card who has found tremendous political success by ignoring the traditional rules of politics. He will say or do whatever he thinks is best in the moment. And Harris, who has dedicated several days to debate prep, can't make a plan for everything.

At this point, it's hard to imagine Trump surprising anyone with new material. He has praised dictators, talked about genitalia size, suggested suspending the U.S. Constitution and said that Harris only recently “turned Black.”

Trump's own team doesn't know what he'll do or say on any given day. That's incredibly risky for Trump. But it also puts enormous pressure on Harris.