From the moment Vice President Kamala Harris walked onto the debate stage in Philadelphia on Tuesday night, it was clear she was on a singular mission: to get under former president Donald Trump’s skin.

She walked directly up to Trump, and into his space, to shake his hand — a maneuver a Harris campaign official described in a text as a “power move.” She used an analysis by his alma mater — the Wharton School at the University of Pennsylvania — to rebut his economic plan. And she rattled off some of the 200 Republicans who have worked for previous Republican presidents and nominees but who have endorsed her over Trump, their party’s standard-bearer.

“If you want to really know the inside track on who the former president is — if he didn’t make it clear already — just ask people who have worked with him,” Harris said, gaining momentum. “His former chief of staff, a four-star general, has said he has contempt for the Constitution of the United States. His former national security adviser has said he is dangerous and unfit. His former secretary of defense has said the nation, the republic, would never survive another Trump term.”

And that was all in the first 30 minutes. She later mentioned the “late, great John McCain,” whom she knows Trump despises. She talked in detail about Trump’s criminal convictions and that he was found liable for sexual assault in New York. She talked about him losing the 2020 election repeatedly. She talked about his response to the white supremacist riots in Charlottesville in 2017, widely viewed as a low point in his first term. She repeatedly brought up Project 2025, a right-wing plan written by his allies and advisers that he has denounced.

A Harris campaign official described the effort as part of a multiday strategy — including an ad released Tuesday morning featuring former president Barack Obama mocking Trump’s obsession with crowd size — that her team hoped would ensure that Trump walked onto the debate stage “triggered.”

In that, Harris largely succeeded.

Trump’s advisers had tried to prepare him for personal insults and attacks on his past — especially his various criminal indictments — and he began the debate calmly enough, seemingly determined to half scowl, half stare straight ahead through Harris’s answers, refusing to take her bait. Much of the debate prep — billed as “policy sessions” — was about getting him ready for the personal attacks and preparing policy rebuttals.

“Kamala Harris came in rehearsed. She delivered the prepared lines that her handlers gave her but she didn’t answer a single question on the issues,” Danielle Alvarez, a Trump campaign spokeswoman, said.

But Trump simply couldn’t resist. The former president gets particularly irritated when Democrats bring up his former advisers who have publicly turned on him — especially John F. Kelly, the former White House chief of staff to whom Harris alluded — and he became more animated Tuesday night when Harris ticked through a list of his former advisers and their rebukes.

“I fired most of those people, not so graciously,” he said.

Later, when Trump attacked Harris on immigration, falsely alleging that Biden-Harris policies had allowed migrant crime to run rampant, the vice president was ready with a well-practiced retort.

“I think this is so rich coming from someone who has been prosecuted for national security crimes; economic crimes; election interference; has been found liable for sexual assault; and his next big court appearance is in November at his own criminal sentencing,” she said, as Trump, unable to control himself, abandoned his thousand-yard gaze to nod — and then shake — his head dismissively, before accusing her without proof of being behind the charges.

But if Harris landed any knockout blow — at least to Trump’s own psyche — it was when she invited viewers to attend “one of Donald Trump’s rallies,” which she called “a really interesting thing to watch.” She mocked him for regularly talking about Hannibal Lecter, the fictional serial killer, and for claiming that windmills cause cancer — and then she went in for the kill.

“And what you will also notice is that people start leaving his rallies early out of exhaustion and boredom,” she said.

At this, Trump’s eyes flared, his eyebrows arched high. Harris continued to make her point — “The one thing you will not hear him talk about is you,” she said — but Trump was already agitated. He dismissed a question from the moderator, saying he wanted to respond to her rally comment.

“She said people start leaving,” Trump said. “People don’t go to her rallies. There’s no reason to go.”

Rep. Byron Donalds (R-Fla.) praised Trump’s debate performance in the spin room following it. But he also acknowledged some skill on Harris’s part. “What we learned tonight is that Kamala Harris is actually probably pretty good at needling people,” he said.

As the debate continued, Harris continued to do just that. She described herself as a “middle-class kid raised by a hardworking mother,” and as someone who, unlike Trump, knows “not everybody got handed $400 million on a silver platter and then filed bankruptcy six times.” And she repurposed Trump’s signature line from his signature show, “The Apprentice,” to rebut his repeated false claim that the 2020 election was stolen.

“Donald Trump was fired by 81 million people,” she said. “So let’s be clear about that. And clearly he is having a very difficult time processing that.”

Trump again said the election was stolen from him, repeating a claim many on his team do not believe is popular with general election voters.

But by then, already off-kilter and having lost at least some of the self-restraint his aides hoped he’d display, Trump was already playing on tilt.

Returning to immigration, a weakness for Harris, Trump instead repeated false claims that Haitian immigrants in Springfield, Ohio, were eating pets.

“In Springfield, they’re eating the dogs,” Trump said, in a claim that prompted a real-time fact-check — false — by one of the debate moderators. “The people that came in — they’re eating the cats. They’re eating, they’re eating the pets of the people that live there.”

At another point, he used dismissive language to portray immigrants in broad strokes, saying, “They can’t even speak English. They don’t even know what country they’re in practically.”

When Harris said that “world leaders are laughing at Donald Trump,” and that military leaders, including some who have worked with him, have called him “a disgrace,” Trump’s response was to invoke an authoritarian, Hungarian Prime Minister Viktor Orban, as a de facto character witness.

Trump’s advisers have encouraged him not to repeatedly bring up the 2020 election — and his false claim it was stolen — as well as his defense of the deadly Jan. 6, 2021, attack on the U.S. Capitol.

They wanted him to avoid his obsession with the Democratic Party replacing President Joe Biden with Harris as the nominee, following Biden’s disastrous debate performance in June. Instead, they have urged him to focus on policy issues, which they believe will accrue to his political benefit.

Yet on Tuesday night, Trump’s execution of those goals was mixed. At times, he moved to attack Harris on policy, but he also repeatedly found himself defending and engaging on those topics his team wanted him to avoid.

“It’s important to remind the former president: you’re not running against Joe Biden,” Harris said. “You’re running against me.”

After the debate, Trump’s allies tried to spin his performance. He came to the spin room himself, citing unnamed polls that he’d won. Rep. Michael Waltz (R-Fla.) said Trump’s critics had expected him to be nasty and personal — but in fact it was Harris who did that.

“It was actually her,” Waltz said. “She went very personal.”

Former congresswoman Tulsi Gabbard, who extensively prepared Trump for the debate, said his anger wasn’t surprising.

“He’s not a fake politician who delivers recited lines like Kamala Harris does. And he cares a lot about the things that he’s doing. So I’m not surprised that he lets a little emotion out sometimes,” she said.

Sen. Lindsey Graham (R-S.C.) was slightly more candid, noting that Harris’s “goal was to rattle him — her goal was to bait him.”

“There were points where he got a bit rattled, but not to the point he lost the point he was trying to make in total,” said Graham, who added that Trump was best when he talked about policies and her record.

Still, Graham conceded: “It could have been better.”

Isaac Arnsdorf and Hannah Knowles contributed to this report.