Mr. Johnson helped circulate a letter, signed by more than three dozen Republican county and state committee leaders, which was addressed to Mr. Trump and asked him to block approval. It states that Mr. Vance is not a registered Republican and provides Mr. Trump with a list of negative comments Mr. Vance has made against him in the past, including calling him “another opioid” in 2016 and saying he hoped Mr Trump would be “soundly defeated” that year.
“While we worked hard in Ohio to support you and make America great again, JD Vance was actively working against your candidacy,” the letter reads. “He called your supporters ‘racists’ and proudly voted for Evan McMullin in 2016.”
Carroll County Republican Party Chairman Jeff Mangun, who signed the letter and did not endorse anyone in the Senate primary, echoed concerns about Trump’s possible endorsement of Mr. Vance. “The best-case scenario is for him to remain neutral, but even if he were to endorse someone, I would prefer someone else,” Mr Mangun said. “I just don’t think it’s a good fit.”
Asked about the accusation that Mr. Vance is not a registered Republican, a Vance campaign spokeswoman pointed to a poll that showed Mr. Vance in second place behind Josh Mandel, a former state treasurer from Ohio; a tweet from a Republican County Chairman denying signing the letter; and another tweet from anti-abortion group Ohio Right to Life PAC which voiced support for Trump’s endorsement of Mr. Vance.
In stump speeches, Mr Vance was quick to respond to criticism that he has not always been a Trump loyalist, often saying the best policy is honesty.
“I didn’t like Trump six years ago,” he told a small crowd of supporters this week at a beer hall in Hilliard. “I didn’t think he was going to be a good president. I was very happy to be wrong.
He added: “I was very proud to support the president over the past few years.”
Mr. Trump has been headed for Mr. Vance for some time, according to the four Republicans familiar with his advisers’ talks. He has been encouraged by a series of allies and donors, including billionaire Peter Thiel, who is one of Mr Vance’s main backers. Fox News host Tucker Carlson, who is influential with members of Mr. Trump’s base, also spoke favorably of Mr. Vance on his prime-time show.