The June 27 presidential debate between President Joe Biden and former President Donald Trump was arguably one of the most influential in modern history, and led to Biden dropping out of the race on July 21, less than a month later. The contest has since changed dramatically, with Vice President Kamala Harris at the top of the ticket and surpassing Trump in the polls, suggesting she may be overcoming some of the shortcomings voters saw in Biden’s campaign.

Now it is time for a new debate.

Harris enters this debate with a relatively high approval rating and a narrow lead in national polls, as well as a surge of enthusiasm among her base following the Democratic National Convention in late August. Her performance Tuesday night in Philadelphia could either continue or halt the upward trend, especially since more undecided voters than usual are likely to tune in.

With that in mind, we dug through the numbers to see what’s on voters’ minds heading into the first presidential debate between Harris and Trump. Recent polls suggest that voters view Harris’ campaign fairly positively so far and think she’s favored to win the debate. Trump, meanwhile, still holds an edge on some of the biggest issues voters are weighing in on, but he may be vulnerable to the same ageist attacks his side once leveled at Biden.

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Since she became the presumptive Democratic nominee, Harris’s approval rating has skyrocketed. At the latest average of 538, it’s around 46 percent, just below her disapproval rating. That’s much better than where she was just before Biden withdrew, when she was underwater by about 15 points:

Harris’s rise in popularity is a notable improvement over Biden, who has hovered around a net popularity rating of -15 for most of this year, and it’s also significantly better than Trump, whose rating has been largely flat since the start of 2024. In our most recent average, he’s still nearly 10 points underwater (53 percent view him unfavorably, 43 percent favorably).

In an ABC News/Ipsos poll conducted Aug. 23-27, 56 percent of adults said Harris is doing an excellent or good job campaigning, compared with 41 percent who said the same of Trump, and 53 percent said she is very or somewhat qualified to serve as president, compared with 47 percent who said the same of Trump. And in the all-important horse race, she currently leads Trump by about 3 points in the national polling average of 538 head-to-head matches — though her momentum appears to have stalled or declined somewhat in recent weeks:

We appear to be at the end of a honeymoon period for Harris’s campaign, and polls suggest that’s because her candidacy has energized some of the many voters who were disillusioned and unenthusiastic about the Trump-Biden rematch. In that same ABC News/Ipsos poll, 64 percent of her supporters said they strongly supported her, compared with just 34 percent who said the same about Biden in early July. Forty-five percent in the August poll also said they were very or somewhat satisfied with the choice between Harris and Trump for president, compared with just 28 percent who said the same about Biden and Trump in July.

Voters also appear to be carrying their positive feelings about Harris into their expectations for the debate. In the ABC News/Ipsos poll, a majority of respondents (43 percent) said they expect Harris to win Tuesday’s debate, compared to 37 percent who said they expect Trump to win. That’s a reversal from the previous debate, where voters expected Biden to fare poorly (and worse than Trump) even before the debate. While higher expectations are a good sign for how Harris’ campaign is doing, they also likely mean she faces a higher bar than Trump when it comes to impressing voters and meeting expectations. That’s one reason why this week’s debate could be crucial in determining whether Harris’ honeymoon period translates into sustained gains or a fiasco.

So, what should voters expect from Harris and Trump in the debate? On the issues, both candidates will try to maintain their positions on issues where they have an advantage, while reducing their opponents’ leads on weaker points. In some ways, Trump starts out with the lead on key issues. The ABC News/Ipsos poll showed Trump with an 8-point lead over Harris when it comes to who Americans trust more to handle inflation and the economy. Trump also held a 9-point lead on immigration at the U.S.-Mexico border, and a 7-point lead on handling the war between Israel and Hamas.

Harris holds an even bigger advantage over Trump on her strongest issues in this poll: 16 points on abortion and race relations, and 10 points on health care. But other recent polls have shown that voters view those issues as less important in determining their vote than the economy and immigration. (Health care and abortion were just behind those two issues on a similar list, while race relations was among the least important to voters.) We expect both candidates to address the big issues like abortion (for Harris) and immigration (for Trump), but we’ll also be watching to see how Harris attempts to change the narrative on the economy and immigration — and how well Trump stays on topic to bolster his advantage on those issues.

Of course, debates are often as much about style as substance: Voters pay close attention to how the two candidates conduct themselves onstage, or who seems more “presidential.” And when it comes to personal qualities, Harris generally outperformed Trump. Respondents in the ABC News/Ipsos poll rated her notably more honest and trustworthy than Trump, 43 percent to 25 percent, and she came out on top when respondents were asked which candidate represents their personal values ​​and understands the struggles of people like them.

Notably, Harris also beat Trump by a wide margin when it came to who Americans think is in the best “physical health” and “mental acuity” to serve effectively as president, with more than twice as many saying Harris was in better physical health (57 percent to 25 percent). That gap underscores one of the most obvious ways Harris’ candidacy changed the dynamics of this race — she is about 20 years younger than both Biden and Trump — and raises the question of whether Trump will face the same age-related concerns that drove Biden out of the race.

There is little traditional about this presidential election, and after a first presidential debate opened the race in June, this one is expected to draw more attention than usual. In an unusually close race between Harris and Trump, the candidates have had little time to make their case to voters, and this week’s debate will be one of the most high-profile and important opportunities to do so. The country will be watching to see whether Harris lives up to the lofty expectations and how Trump responds in their first head-to-head.