Two months and one political lifetime ago, Donald Trump’s supporters rushed to the cameras gathered in Atlanta after his debate against Joe Biden to crow about his obvious victory. For a while, there was no Biden representation in the spin room at all as the president’s morose surrogates like Gavin Newsom and Raphael Warnock hung back, caucusing with campaign officials about how on Earth to paint the night as anything other than a catastrophe for Democrats. On Tuesday night in Philadelphia, however, the spin room lit up before Trump even finished his closing statement. Out first was Pennsylvania’s hyped-up Democratic governor Josh Shapiro, there to declare the debate a resounding success for Kamala Harris.

For the second debate in a row, everyone with eyes and ears could interpret for themselves what had happened on stage. (Spin rooms are awful by design—which self-respecting journalist needs campaign-selected talkers to tell their audience that their candidate did great and their opposition is a moron?—but campaigns know that many voters are influenced by press coverage and try to seed storylines to any reporter who’ll listen.) One Harris aide shrugged to me that his job was easy: No one had real questions for him and the campaign’s attention was already elsewhere; the candidate herself was off celebrating with supporters, and the TV networks were showing her party live. Trump’s handpicked cheerleaders, meanwhile, tried pivoting everything back to the border, just like he had all night.

I gave it half an hour or so, but the big gaggles forming around the likes of Matt Gaetz and Vivek Ramaswamy weren’t enough to keep me there. The spectacle seemed tired, and no one was learning anything new. Just as I was walking out, two of Trump’s top advisors, Jason Miller and Chris LaCivita, rushed in past me. I overheard LaCivita say that “he” was coming to the spin room — “he” was obviously Trump.

The former president appeared a few minutes later, lowering himself to spin duty, desperate as ever for the cameras and microphones. It was clearly not a sign of great confidence that he was in control of the evening’s narrative, but there wasn’t much he could do at this point, though once again he couldn’t help himself. Trump’s hair was fixed up, his scowl slightly lighter than it had been on stage now that he was in his natural habitat with hundreds of reporters surrounding him and dozens of cameras in his face. He didn’t have much to say. Lindsey Graham had already started suggesting that he fire his debate prep team after the evening’s “disaster” and Trump himself had already started whining about the moderators. But he found Sean Hannity and did some more of that, and said he’d won anyway, and complained about the border and the fact that Harris had prepared for the debate, and waffled about doing a second one. It was a fittingly flat end to his night, especially since he was in the process of getting upstaged yet again. As Trump spoke, the room’s attention drifted. About half of the people left opened Instagram to see Taylor Swift’s endorsement of Harris.

Harris had not come to Philadelphia expecting to land a knockout punch on Trump. Instead, she came prepared with a list of clearly defined points to hit, each planned out to reach different defined segments of the voting population that are still curious but wary about her in their own ways. And for nearly two hours onstage, with Trump glaring at his lectern just feet away, she pursued them methodically.

In the weeks of her vertiginous rise, the vice president’s biggest challenge has shifted from introducing herself to voters to arguing that she, not Trump, is the change agent in the race. In the days leading up to the debate, I asked an array of her allies to identify the audience it was most important for her to reach on Tuesday. One top party financier immediately replied “Nikki Haley Republicans,” a longtime friend in politics said she still had to convince some young voters she was on their side, and a senior Democratic pollster told me her top objective had to be convincing older voters. All agreed, however, on the fundamental message these groups had to hear: that she is a serious, steady, and energetic leader who can move the country past the Trump era. “There are voters who don’t yet know who the vice president is, what her leadership journey has been,” California senator Laphonza Butler, a former Harris aide and longtime confidant, said shortly before Harris walked onstage.

Immediately, it was clear that Harris saw rattling Trump as central to that goal, convinced that the angrier he got, the easier it would be for her to present the contrast. Immediately, she walked straight up to Trump on stage and introduced herself as she shook his hand—a moment he clearly didn’t expect or know how to handle.

It took only a few minutes for Trump to grow flustered by Harris’s reference to a negative analysis of his economic plans by professors at Penn’s Wharton School, his alma mater. Minutes later, she directly quoted a tweet of his praising Chinese leader Xi Jinping over Beijing’s handling of COVID, and he once again spluttered. Soon after, he mixed up Virginia for West Virginia when he went on a tirade about Democrats and “after birth” abortion. He also praised the “genius and heart and strength” of the six conservative Supreme Court justices who overturned Roe v. Wade—a historically unpopular move. As Trump refused to make eye contact with Harris and grimaced into his notes, I was reminded of what Celinda Lake, a senior Democratic pollster who works with the Harris campaign, told me a few hours earlier: Research shows that 70 percent of what voters take away from debates is the theater aspect, only 30 percent is the actual policy difference.

Harris’s campaign relished the chance to throw Trump off his game after he won the first debate against Biden by simply letting his opponent expose himself as just too old for the job. This time, the Harris team ran an ad on Fox News and stationed billboards around the city taunting Trump about his smaller crowd sizes, an obsession of his that voters find childish. When Trump accused her of busing in paid crowds to her own events, Harris looked like she almost couldn’t believe he took the bait instead of responding to her claim that he doesn’t care about everyday voters. She laughed as Trump insisted that undocumented migrants were eating family pets in Ohio, a far-right conspiracy that took his focus far from his straightforward attempts to blame her for the migrant surge at the southern border. One top Democratic operative, who’d been basically comatose at that point early in the first debate, started texting me “YES” “YES” “YES” every few moments as Trump preached to the far-right corners of X more than persuadable voters in swing states.

“Talk about extreme,” Harris began after Trump’s claims about pet-eating, before appealing to Haley voters by listing off her endorsements from former GOP officials, including Dick Cheney and a series of Trump’s own former national security aides. Her point was that he is erratic and can’t be trusted, and she isn’t and can. Her biggest accomplishment, the top operative told me, was making Trump look exhausted, exhausting, and out of touch with regular people, an argument that resonates especially with moderates who simply want to move on from him, no matter if they agree with some of his policies.

Still, it was independents and older voters who she courted most clearly in her set-piece moments. “Seniors are watching the debate more, and she is softer with seniors — they worry about her qualifications and have some sexist and racist assumptions about that,” Lake said a few hours before showtime. “They underestimate her strength and they’re not sure what her plans are, they’re nervous about her, they see her as less change and more risk.”

Since the Democratic convention in Chicago, Harris has tried appealing to seniors in particular by painting herself as a stateswoman, talking with increasing specificity about her meetings with foreign leaders. And when Trump refused to answer directly whether he wanted Ukraine to beat Russia, she launched into patriotism: Giving up on Ukraine, she said, is “not who we are as Americans.” She spoke about her meetings in the region and “the air defense, the ammunition, the artillery, the javelins, the Abrams tanks that we have provided” to Kyiv to make sure Russia can’t roll over Ukraine and into the rest of Europe. After the debate, deputy campaign manager Quentin Fulks made sure I’d caught that Harris had specifically brought her answer around to “the 800,000 Polish Americans right here in Pennsylvania.” (She also went out of her way to insist she no longer opposed fracking, a sensitive issue in rural Pennsylvania.)

Throughout the evening, the Harris campaign had a group of undecided voters in the battleground states reporting their feelings about what was happening onstage in real time. Such “dial testing” is standard practice, but campaigns don’t tend to share any details of how that testing is going if things aren’t going well. On abortion, he insisted Democrats were open to executing infants, claimed credit for overturning Roe, and refused to say whether he’d oppose a nationwide ban, while she spoke about women affected by the bans. David Plouffe, one of her senior-most advisors, revealed that there was a 40-point gap between the voters’ approval of the candidates’ answers during this exchange. “Widest gap I’ve ever seen in debate dials,” he said.

Only later did the Harris campaign’s private testing confirm one of the central underlying hypotheses of her candidacy: that Americans are tired of the Trump era, and want to believe a new political age is possible. The debate’s low point for these voters, according to the dials, was when Trump once again claimed to have won the 2020 race as part of a longer conspiratorial ramble. Its high point for Harris was when she replied to Trump’s spurious claim that she hadn’t always identified as Black by detailing his history of racism, such as calling for the execution of the Central Park Five, before ending on an up beat: “The American people want better than that. Want better than this.”

Ever since Harris became the presumptive Democratic nominee, Republicans have dismissed the excitement around her, saying there is a big difference between vibing with partisans and actually convincing voters. Once Harris’s poll numbers started to flatten out this month, it became obvious that this was a big part of her challenge: convincing this final decisive slice of the electorate that she’s up to the job of president and that she’s sufficiently different from Biden. In front of her biggest audience yet on Tuesday, Harris succeeded in making the case.