What Harris, Trump need to do to win Tuesdayâ€s presidential debate

When Vice President Kamala Harris and former president Donald Trump share the debate stage Tuesday night, voters will have their first and possibly only chance to view both candidates side-by-side in a matchup that started just about seven weeks ago, when President Joe Biden dropped out of the race. The stakes are high as Harris and Trump remain locked in an incredibly tight contest, days before ballots are mailed out in some key states.

We already know a lot about how each candidate debates and their likely weaknesses on the stage. Harris is perceived as a quick-witted debater but could be on the defensive about her recent position shifts as she courts general election voters. Trump won the last debate of this election — but against a very different candidate.

(You can watch the 90-minute debate starting at 9 p.m. Eastern on ABC Newsâ€s properties, including ABC News Liveâ€s streaming online, Disney Plus and Hulu. The Washington Post will have coverage of the debate beginning at 8 p.m. Eastern.)

Hereâ€s what each candidate needs to do — and avoid doing — to be seen as the winner.

Harris needs to define herself as something new, not more of the same

Harrisâ€s job in this debate is pretty simple (although not easy), say Democratic strategists: She needs to tell voters who she is, what she stands for and what kind of president she would be.

She has pitched herself on the campaign trail as a realist who can be trusted to use common sense. But in her 2020 primary run, she struggled to articulate clear positions and has been criticized for appearing to switch sides under political pressure. For example, some voters in Pennsylvania worry she canâ€t be trusted after opposing fracking while running in the 2020 Democratic presidential primary. She now says she wouldnâ€t try to ban it.

“A lot of people will watch the debate and ask themselves: ‘Can I see Kamala Harris in the role of president?â€â€� said Democratic strategist Tim Hogan.

The candidate who will win the election is the candidate seen as the most able to bring about change, say strategists on both sides. A New York Times/Siena College poll found 61 percent of likely voters said they want major change from Biden. Democrats argue Harris inhabits an ethos of change simply by being a younger, fresher candidate, and her potential to become the first woman president. They hope Trump will look stale on the stage next to her.

“You saw her get a bump when the Democratic Party was able to meet that desire for a change ticket that the Republicans couldnâ€t,â€� said Pennsylvania-based Democratic strategist J.J. Balaban.

Yet Trump is expected to make the case that Harris will be a continuation of the Biden presidency and canâ€t be trusted. So far, Harris hasnâ€t strayed far from Bidenâ€s positions, offering proposals that build on his economic and social work.

Harris needs to bring her prosecutorial style to Trump, but not get dragged down

Harris is viewed as a sharp debater, capable of reading the room and offering a viral quip in an unexpected moment, say those who have watched her debate for years. In the Senate, she took a courtroom-style approach to questioning Trumpâ€s Supreme Court nominees, getting Brett M. Kavanaugh to admit he couldnâ€t think of any laws that govern a manâ€s body.

But as she prosecutes Trump, Harris needs to avoid being drawn into an ugly back-and-forth with him. Itâ€s one of the tougher parts of debating him, Democrats say, because he will inevitably throw out myriad falsehoods and attacks that are tough to leave unanswered. But Harris may simply not have time to respond to every claim he makes.

“You have to parry his attacks and you have to push back,â€� said Hogan, “but you also donâ€t want to get stuck there.â€�

It will be Harrisâ€s first presidential debate, although she did participate in a vice-presidential debate in 2020 and multiple primary debates. By contrast, this will be Trumpâ€s seventh presidential debate in a general election.

“Trump has been hit 1,000 times,â€� said Stan Barnes, a former Republican state senator in Arizona and a political consultant. “But she has not withstood scrutiny in the public sphere from an adversarial opponent. Iâ€d much rather be Trump in this debate than her.â€�

Trump needs to avoid attacking Harrisâ€s race and gender

And he needs to just generally avoid becoming flustered, say strategists on both sides.

Thatâ€s because Trump doesnâ€t have to go after Harris personally, Republicans say. Many think if itâ€s an election focused on the issues, he wins. “He needs to focus on what has led to immense voter dissatisfaction across America,â€� said Republican strategist Jesse Hunt. “There is a very clear path to victory here, and it is holding Kamala Harris accountable for a terrible record in office with Joe Biden, and all of her past positions that her campaign team has now deemed incredibly unpopular.â€�

For this, the format of the debate favors Trump: Just as in his debate against Biden, the microphones will be off when itâ€s not his turn to speak, preventing him from interrupting Harris to interject an insult that might come across as bullying.

Trump needs to come up with an answer on abortion

Trump seems keenly aware his party is on the wrong side of public opinion on abortion. Yet when he is talking about it, he often agitates his social conservative base or alienates swing voters as he appears to flip-flop. Recently, he indicated he would vote in Florida for an amendment protecting abortion rights until viability (which is around 24 weeks of pregnancy) — then said he wouldnâ€t under pressure from social conservatives to support Floridaâ€s six-week ban.

As he fumbles on what to say about abortion, Trump has also been struggling to win over female voters. A recent CNN/SSRS poll shows Harris leading Trump by 18 points among suburban women in Pennsylvania, and these are the voters who could help decide this election.