The Ohio senator campaigned at his former high school in Middletown before an evening stop in Radford, Virginia, two venues intended to play up his conservative populist appeal across the Rust Belt and small-town America that he said the Biden-Harris administration has forgotten.

“History will remember Joe Biden as not just a quitter, which he is, but as one of the worst presidents in the history of the United States of America,” Vance said in Virginia. “But my friends, Kamala Harris is a million times worse and everybody knows it. She signed up for every single one of Joe Biden’s failures, and she lied about his mental capacity to serve as president.”

Vance sought to saddle Harris with the administration’s record on inflation and immigration, clarifying the lines of attack that the Trump campaign will use even with the change at the top of the Democratic ticket. Harris still must be formally nominated but has quickly consolidated commitments from top party leaders and is now backed publicly by enough delegates to win her party’s nomination vote, according to an Associated Press survey.

“The border crisis is a Kamala Harris crisis,” Vance said, accusing Biden and Harris together of rolling back immigration policies that Trump enacted in his White House term. He added Harris is “even more extreme than Biden” because, Vance alleged, she has designs on abolishing federal immigration enforcement and domestic police forces.

Vance, 39, drew biographical contrasts with Harris, as well, comparing his service in the Marine Corps and small business ownership to Harris “collecting a government paycheck for the last 20 years.”

Harris, 59, was a local prosecutor, then California attorney general and a U.S. senator before she ran for president unsuccessfully in 2020 and became Biden’s running mate. Vance was elected to the Senate two years ago.

Vance also fulfilled his role as Trump’s biggest cheerleader, promising the former president would lead an era of peace and prosperity in a White House encore, while helping Republicans dominate House, Senate and state contests.

“We’ve got an opportunity to win races up and down the ballot,” he said.

He promised, “You’re going to see more and more products stamped with that beautiful logo: ‘Made in the USA.’” He also asked the crowd, “Who is sick of sending America’s sons and daughters into foreign lands they have no business in?”

The senator carefully stopped short of outright isolationism, however, pledging the U.S. would “punch back hard” when necessary. Vance did not detail any policy approach to the wars that have most vexed the Biden administration: Vladimir Putin’s Russian invasion of Ukraine and the Israel-Hamas war in Gaza.

Those arguments are at the core of Trump’s “America First” brand and highlight Vance’s electoral strengths as the son of Appalachia who first came to national prominence with his memoir, “Hillbilly Elegy.” Trump’s campaign intends to use him heavily across the Rust Belt and swaths of small town America where voters have moved to the right and remain especially frustrated over decades of what Vance called “bad trade deals.”

Trump and Vance sat Saturday for a joint interview with Fox News that was aired Monday evening after the senator’s rallies. Trump nodded to the fact that Vance, during his brief political career, has morphed from being a harsh Trump critic, at one point likening him to Adolf Hitler, to a staunch defender.

“Originally, JD was probably not for me, but he didn’t know me,” Trump told Fox host Jesse Watters as Vance looked on. “And then when we got to know each other, he liked me maybe more than anybody liked me, and he would stick up for me. … We just had an automatic chemistry.”

Earlier Monday in Ohio, Vance tried to deflect the criticism that Trump, who has refused to accept his 2020 loss to Biden and tried to overturn the results, is a threat to democracy. The senator claimed that the real threat came from the push by “elite Democrats” who “decided to throw Joe Biden overboard” and then have the party line up behind a replacement without primary contests.

Democrats, he said in Virginia, lied “for three-and-a-half years” only to “pull a switcheroo.”

While Republicans promoted a unifying message at the Republican National Convention where Vance was nominated last week and decried inflammatory language in the wake of the assassination attempt against Trump, one of the first speakers to introduce Vance in Ohio suggested the country may need to come to civil war if Trump loses in November.

“I believe wholeheartedly, Donald Trump and Butler County’s JD Vance are the last chance to save our country,” said George Lang, a Republican state senator. “Politically, I’m afraid if we lose this one, it’s going to take a civil war to save the country and it will be saved. It’s the greatest experiment in the history of mankind.”

Lang later apologized after Harris’ team highlighted his remarks on a post on X.

“I regret the divisive remarks in the excitement of the moment on stage,” he said on the same social network. “Especially in light of the assassination attempt on President Trump last week, we should all be mindful of what is said at political events, myself included.”

Vance still has work to do raising his profile. A CNN poll conducted in late June found the majority of registered voters had never heard of Vance or had no opinion of him. Just 13% of registered voters said they had a favorable opinion of Vance and 20% had an unfavorable one, according to the poll.

After Vance was named as Trump’s running mate, a startling number of Republican delegates, who are typically party insiders and activists, said they did not know much about the senator.

In his hometown in Ohio, though, he was welcomed as a local star.

Darlene Gooding, 77, of Hamilton, said Vance will provide a welcome contrast to Trump.

“Trump doesn’t always come off the best. It’s all about him,” she said. “JD is wonderful. He gives you the idea he really cares about people.”

In Virginia, Trump backers were warming quickly to his new running mate.

Pamela Holloway, who came to see Vance in Radford, described herself as a former Democrat who has gravitated to Republicans. She said she recently bought Vance’s book to learn more about how his experiences have shaped his political outlook.

“He’s truthful,” she said of his writing. “He talks about his mother being an addict. He talks about the hardships with his grandmother” who raised him. “He talks about things that aren’t fake.”