In a Fox News interview Sunday, Sen. JD Vance responded to criticism of him being picked as former President Donald Trump’s running mate, saying he takes it as a "badge of honor."

"All I can do is go out there and prosecute the case against Kamala Harris to remind people that things were more prosperous and more peaceful when Donald Trump was president," Vance said. "Look, I recognize there are a lot of folks even in the GOP establishment and certainly on the far left who don't like the fact that Donald Trump picked me, I actually take their criticism as a badge of honor."

Vance also hit back at Democrats who’ve called him "weird," calling it "a lot of projection."

"They can call me whatever they want to. The middle school taunts don't bother me," he said. "What offends me is what Kamala Harris has done to this country over three and a half years."

-ABC News' Lalee Ibssa, Soo Rin Kim, Kelsey Walsh and Hannah Demissie

Vice President Kamala Harris' presidential campaign announced Sunday that it would be launching a "Republicans for Harris" program aimed at reaching Republican voters who could be convinced to vote for Harris. The program will include digital advertising, phone banking, events and other initiatives, according to the campaign.

The program -- and Harris herself -- have been endorsed by a number of Republican figures, including former Trump White House press secretary Stephanie Grisham.

"I might not agree with Vice President Kamala Harris on everything, but I know that she will fight for our freedom, protect our democracy, and represent America with honor and dignity on the world stage," Grisham wrote in a statement released by the Harris campaign.

The "Republicans for Harris" program will hold kickoff events starting this week, per the campaign.

-ABC News' Gabriella Abdul-Hakim, Fritz Farrow, Will McDuffie and Oren Oppenheim

Vice President Kamala Harris plans to meet with some of the top vice presidential contenders in person in Washington, D.C. this weekend, including Gov. Josh Shapiro, sources familiar with the matter told ABC News.

One source, who spoke to Shapiro yesterday, said he canceled everything on his schedule this weekend for Harris. He also canceled his appearance at a previously scheduled commissioner’s meeting at his own residence next week, the source added.

Shapiro said he was feeling "super confident," according to the source.

-ABC News' Selina Wang

The Harris campaign has hired a slew of new senior advisers this week, including multiple leaders from former President Barack Obama's campaign, according to people briefed on the campaign shifts.

Stephanie Cutter, Obama's former deputy campaign manager will take on the role of senior adviser message and strategy, Mitch Stewart, a former Obama grassroots organizer, will become the senior adviser for battleground states, and David Plouffe, one of Obama's top strategists, will end his ties with TikTok and his podcast to become the senior adviser for path to 270 and strategy, the sources said.

The news was first reported by Politico.

The Harris campaign is also bringing on Terrance Woodbury of HIT Strategies, a specialist in Black voter opinion research. Quentin Fulks, the principal deputy campaign manager for Harris, will take over leadership of the campaign’s advertising program with the current paid media team.

"We’re thrilled to expand her team with these battle-tested leaders that know her and know how to win close elections. Together, we will harness the historic enthusiasm and support we’re seeing to do the work in reaching the voters who will decide this election – because when we fight, we win," campaign chair Jennifer O'Malley Dillon said in a statement.

-ABC News' Gabriella Abdul-Hakim, Fritz Farrow, Isabella Murray and Will McDuffie