Republican vice presidential nominee JD Vance used his first solo campaign rallies Monday to throw fresh barbs at Vice President Kamala Harris a day after President Joe Biden threw the presidential election into upheaval by dropping out and endorsing his second-in-command to lead Democrats against Donald Trump.

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.