The debate between Vice President Kamala Harris and former President Donald Trump on September 10 will be the second such face-off in the 2024 election – but the first in which Harris runs rather than President Biden, who ended his campaign just over a month ago.

The stakes couldn’t be higher. As anyone who follows US politics knows by now, Biden’s shaky performance on June 27 was pretty much the reason He dropped out of college a few weeks later.

In other words, these quadrennial spectacles can have very real consequences for the candidates — and that’s especially true for Tuesday’s debate, which may be the only time Harris and Trump will face off before voters start casting their ballots. (No other presidential debates are currently scheduled.)

So what do Harris and Trump need to accomplish in Philadelphia? Here’s a quick Yahoo News guide.

What Harris must achieve

Take a moment… The climax of Harris’ otherwise unsuccessful attempt to win the Democratic presidential nomination in 2020 actually came on the debate stage.

In the first clash of this cycle, Harris sharply criticized then-opponent Biden for working with segregationist senators in the 1970s to oppose state-mandated school bus transportation.

“There was a little girl in California who was in the second grade that integrated her public school, and she rode the bus to school every day,” Harris said. “And that little girl was me.” The clip went viral – and soon the Harris campaign was selling “That Little Girl Was Me” T-shirts on its website.

Most voters don’t watch these debates live, but rather absorb the high points and low points after the fact, usually on social media. In the past, Harris has shown a knack for creating viral moments — especially when she’s in accusatory mode and grilling Republicans. Do the same to Trump on Tuesday night — perhaps on abortion, an issue he’s recently clashed over — and Harris could be well on her way to a “win.”

… but no slip-up. Harris has also had her fair share of bad moments online. They usually happen when she’s caught off guard – and in response, she starts spouting meaningless, aimless platitudes. Trump uses such gaffes to claim that Harris is uninformed and ill-prepared for the presidency. Fair or not, she needs to avoid serving up more word salad in Philadelphia lest she reinforce that line of attack.

Connect according to policy. Contrary to popular belief, Harris has began to take more concrete policy actions. On August 16, she unveiled a detailed economic program aimed at reducing the cost of food, health care and housing for working- and middle-class Americans. On Wednesday, she announced a plan to tax capital gains and small businesses at lower rates than Biden.

Harris won’t be able to devote all her time to jargon on Tuesday. But, according to Politico, she has a theory on the matter. Just as friends immediately look for photos of themselves in their wedding album, she believes voters should be able to find something for themselves in a candidate’s proposals. Harris’ advisers call it the “wedding album” question — and the vice president would do well to give viewers a few concrete, memorable examples during the debate.

Be the stronger one. Trump isn’t shy about attacking Harris — her competence, her intelligence, her looks, even her biracial heritage. He recently reposted a grossly misogynistic comment about her on Truth Social. But as Trump’s past opponents can attest, he’s not worth wrestling with on the debate stage. (Remember what happened to Florida Sen. Marco Rubio after he mocked Trump’s… hand size?)

Trump is in his element when he’s testing boundaries. So far, Harris has resisted the temptation to take him on. Asked in her recent CNN interview about Trump’s remark that she had only recently “turned black,” Harris said simply, “Same old, hackneyed script. Next question, please.” That kind of “staying out of the fray” approach could help establish her as the more “presidential” option on Tuesday night.

What Trump must achieve

Let Harris beat Harris. Because Trump is such a well-known figure at this point – and because views of him are so entrenched – there is less upside or downside for him than for Harris. Think about it: What could Trump say or do at this point that would change voters’ opinions of him one way or the other?

What Trump really needs to do is change voters’ perceptions of Harris – or let Harris do the work herself.

During his debate with Biden in June, Trump was most effective when he simply avoided the president. “I really don’t know what he said at the end of that sentence,” Trump muttered at one point. “I don’t think he knows either.” As usual, Trump made dozens of false claims that night, but Biden was the big story — in part because Trump was smart enough to cede the spotlight. The best-case scenario for Trump is that Harris stumbles … and that he does nothing to divert attention from her mistakes. Less is more.

Don’t be weird… After Harris succeeded Biden in July — and especially after she named Minnesota Governor Tim Walz as her running mate — the Democrats’ main attack on Trump and his number two, Ohio Senator JD Vance, shifted from “they’re a threat to democracy” to “they’re weird.” Whether you approve of that message or not, “weird” is a lot easier to convey on a debate stage than “dangerous.” If Trump spends Tuesday night saying weird things — about sharks and electrocution, about the “late, great” Hannibal Lecter, about funding child care through tariffs — or simply denying those allegations (over and over again), he will help make Harris and Walz seem normal by comparison.

… particularly in relation to race or gender. Trump often behaves oddly around powerful women. Remember how he stalked the stage during their first debate in 2016, towering over Hillary Clinton. “He was literally breathing down my neck,” Clinton later recalled. “It sent shivers down my spine.” Apparently voters didn’t like that either.

Harris, of course, is black and Indian-American. If elected, she would be the first female president in U.S. history. Harris has chosen not to rely on her groundbreaking identity on the campaign trail, making it implicit rather than explicit. But race and gender are volatile issues, and if Trump decides to “go in that direction” on Tuesday night — as he did, for example, when he recently accused Harris of “going black,” or when he previously said a number of derogatory things about women — it will overshadow the rest of the debate. And that’s probably not good news for Trump.

Stop waving your arms around abortion. Trump, according to the New York Times, has “privately stressed to advisers that … the abortion issue alone could destroy her chances of winning in November” – and since Harris emerged, she has only increased the pressure on a man who has long claimed to be “the most pro-life president in American history” for appointing the Supreme Court justices who Roe v. Wade.

In response, Trump recently attempted to reposition himself on the issue, criticizing the Arizona and Florida bans, watering down the Republican Party’s abortion language, and claiming his administration would be “great for women and their reproductive rights.”

But that has led to accusations on both the right and the left that they are changing their minds. Trump knows that strict abortion bans are unpopular – and that Democrats tend to do better when the issue is front and center. If the former president can clarify his position on Tuesday night, he may be able to somewhat neutralize Harris’ lead. But if he continues to muddy the waters, it will only strengthen her position.