What Harris and Trump Need to Do in Their First Debate

It’s a well-established maxim of political science that presidential debates are rarely game changers, despite the hype that precedes them and the spin they generate. But the ABC-sponsored debate between Kamala Harris and Donald Trump in Philadelphia on Tuesday could prove to be an exception.

First, we saw on June 27 how very consequential a presidential debate can be under certain circumstances. While it’s unlikely that either candidate will have the sort of debilitating meltdown Joe Biden suffered in Atlanta, no one will be able to forget that these are not the same two candidates who originally agreed to a debate on September 10.

Second, the Harris-Trump competition is not the same as the Biden-Trump rematch. The Democratic nominee is not that well known, and both candidates will be eager to define her. In Harris’s case she must combine this with some shots at Trump’s record and extremist agenda (just as Biden did, not that much of anyone noticed).

Third, this is a very close presidential race, which means both base enthusiasm and swing-voter persuasion will be at a premium for each campaign. It’s the sort of contest in which small things could have very large consequences, and the Philadelphia debate may provide a rare opportunity to change minds and inflame hearts.

So other than not melting down, what will each candidate try to accomplish? Here’s a look at what Harris and Trump need to do.

Harris’s goal: reintroduce herself as the candidate of “safe change”

Without question, the Democratic candidate has the more complicated task: defining herself to viewers as an agent of change from the Biden-Trump era of politics, and a much safer option than an extremist second Trump administration. This means anticipating and rebutting Trump claims that she is responsible for Biden’s alleged policy failures and is more radical than Biden himself. And it also means casting some light through the fog of endless commentary about Trump to convincingly express concerns about what he will do if restored to power.

With Biden as the Democratic candidate, the contest was a straight choice between the 45th and 46th presidents. Sour public assessments of the status quo meant the Democrat needed to frighten his party’s base into voting against Trump’s return and persuadable voters into ignoring their own desire for change. Harris has a narrow but very real window of opportunity to convince all kinds of voters that she offers a better option than the status quo or a second chance for the felonious Trump to wreak vengeance on the middle class and on American liberties. Her DNC acceptance speech was a good start, but she needs to sustain its inspiring and reassuring message while under fire from Trump for 90 minutes.

According to my colleague Gabriel Debenedetti’s reporting, Team Harris is resisting the temptation of undertaking a rock-’em-sock-’em back-and-forth with Trump in favor of defining herself more clearly, keeping her cool, and landing blows on the former president that will last longer than snap polls or debate scoring. That likely means sticking to the broad themes and limited policy agenda she has laid out since the DNC. She has focused on abortion rights, living costs and housing availability, and a tough border policy, along with an intelligent, measured foreign policy and an openness to bipartisanship. Harris has also presented a limited critique of Trump, highlighting his responsibility for abortion bans, his recklessness on January 6, and the sinister plans reflected in Project 2025. She can draw on her relatively positive personal image to achieve a credibility advantage over Trump if she doesn’t allow him to drag her too far into the mud.

One question is how far she is willing to go in separating herself from the man who is currently her boss and the unpopular president of the United States. That could be tricky, but it’s very likely Biden has given her plenty of slack to signal a significant departure. He’s actually old enough to remember when LBJ’s vice-president Hubert Humphrey came within a whisker of saving American from a Nixon administration by significantly but not decisively breaking with Johnson on Vietnam. Harris needs that same opportunity.

Trump’s goal: Scare voters about a Harris administration

There is a very good reason that Donald Trump remains angry about the so-called “coup” whereby Biden gave way to Harris as the Democratic nominee: He appeared to be winning the election with the simple argument that life was better for Americans when he was president. It was fortunate for him that a border crisis allowed him to look reasonable and even statesmanlike on his signature extremist issue of immigration, and that the exceptional complexity of economic trends coming out of the pandemic allowed him to pin total responsibility for the economic dislocations of the COVID era itself and the subsequent spike in food and gasoline costs on Biden. He also benefited (and continues to benefit) from his supporters’ acceptance of his argument that the massive legal peril his own conduct invited was in fact no more than partisan “weaponization” of law enforcement. And as his relatively positive favorability ratings (favorable for this famously unpopular politician, that is) show, surviving an assassination attempt has given him an opportunity to rebrand himself a bit, though he hasn’t shown much of an inclination to do so.

When it comes to this debate, Trump’s biggest advantage is the extremely low standard he has set throughout his career for either coherence or civility. Almost anyone else would be afflicted with a dilemma as to whether to accuse Harris of being Biden 2.0 or a “communist,” since Biden is nobody’s idea of a dedicated Marxist-Leninist revolutionary. Trump can blithely pursue both angles of attack simultaneously, because that’s just who he is. Calling Harris a “radical” or a “Marxist” or a “communist” is what passes for a substantive comment from the former president, and he would be wise to stick with ideologically freighted criticism rather than slandering her personally (i.e., he should leave the blatantly racist and sexist patter to MAGA social media).

Above all, the 45th president needs to do everything he can to fan doubts about Harris, making her out to be the “risky change” candidate and returning the election to a competition between highly motivated party bases with swing voters ultimately focused on their unhappiness with life as it is.

Knowing Trump and his operatives, there’s a chance he will try to pull off some sort of distracting trick before, during, or immediately after this debate, just as he did in 2016 when he paraded a row of women who had accused Bill Clinton of sexual misconduct into front-row seats during a debate with Bill’s wife. Perhaps he’ll pull some stunt with his new admirers, the ex-Democrats Robert F. Kennedy Jr. and Tulsi Gabbard (who famously had a viral moment attacking Harris from the left during a 2020 debate). It’s common to refer to Trump as a master of chaos, but another way to look at it is that he is the horse who can create the muddy track on which he runs best. Keeping Harris off-stride and flustered and defensive would suit him as well as any “score” on a point of policy.

When will we know who “won” the debate?

Barring some meltdown or unmistakable rout, the debate is less likely to become a decisive moment. You can safely ignore the spin from both sides that will claim total victory over an opponent who is grievously wounded and weeping in frustration and pain. Debate professors who try to judge the event on some sort of point system are suspect, as are snap polls (again, unless it’s a rout). But we should know pretty soon, from more extensive polling and the conduct of the candidates, whether a debate has altered the course of this election once again.