Former President Donald Trump plans to endorse JD Vance in the crowded Ohio Senate GOP primary, according to three sources with knowledge of his decision.

In recent days, Trump has started calling donors and advisers to get their opinion on the author’s endorsement of ‘Hillbilly Elegy’, but he has resisted under intense pressure from the rival Republican campaigns of Josh Mandel and Jane Timken. , sources said.

“The Mandel people hit the roof,” a Republican familiar with the discussions told NBC News, noting that Ohio Republican Representative Jim Jordan tried to talk Trump out of endorsing it.

The May 3 primary is a winner, meaning the candidate with the plurality advances to the November general election.

Although Trump’s press shop has already drafted an endorsement of Vance, a source close to Mandel’s campaign said Thursday he threw a last-minute hurdle at the former president: an internal Republican poll conducted by Mandel’s campaign showing their candidate ahead with 33% of the vote, followed by Matt Dolan and Mike Gibbons tied at 15%. Vance and Timken were tied at 9%.

The poll showed that, even with Trump’s approval, Vance rose to 15% support but was still tied at three for second place, with Mandel slightly ahead at 19% – a sign that Trump’s approval Trump had weight but was not decisive.

A Trump spokesperson could not be reached for comment.

Trump has been concerned about Vance, who bitterly criticized the former president in 2016. Vance also ranks around third or fourth in recent public polls and has barely hit double digits – a major worry for Trump who doesn’t doesn’t want to waste his endorsement, the sources said.

Dolan is the only candidate running on a platform that doesn’t appear to be courting the former president’s support. This has bothered Trump immensely and made him want to pick a winner to ensure a non-Trump sidekick doesn’t win a state he won hands down in 2020 and 2016.

In public polls, Mandel and Gibbons lead the pack with about 20 percent of the vote each.

But Vance isn’t so far behind in public polls that he can’t catch up. And those who have spoken to Trump or his advisers in recent days say he sees the greatest opportunity for growth with Vance and a chance to make a real difference.

Former Trump campaign and White House adviser Michael Caputo, who recently spoke with the former president, did not reveal the nature of his private discussion, but said the Twitter that reports of Trump leaning towards Vance are “consistent with my conversations.”

Florida Rep. Matt Gaetz, also a Trump confidant, telegraphed word of Trump’s endorsement earlier today saying on Twitter that “JD looks like a guy who would disrupt the establishment, not join it.”

After NBC News reported that Trump planned to endorse Vance, a list of GOP officials in Ohio wrote a letter to Trump urging him “not to support anyone in this race.” Local party officials have explained why they think Trump should hold back from officially endorsing Vance, citing the candidate’s remarks about Trump in 2016, among other things.

Vance supporters, including the former president’s son and namesake, were hoping Trump would have approved on Thursday, when his office announced it was holding a rally in Ohio on April 23, just 10 days before the primary.

“Nothing is final until it is final. So Trump can always change his mind,” said a source who recently spoke to Trump about the race in Ohio. “But he has already given a kick in everyone’s tires and he’s good to go with Vance. It’s either Vance or nobody. And it’s nobody if somehow the other campaigns can keep him waiting.

A source familiar with Trump’s thinking said he also has an affinity for Timken, the former GOP party chairman from the state he helped gain leadership in Ohio in 2017, and he considers her an ally in the state.

This week, a potential reunion was scheduled for Timken at Mar-a-Lago, the source said, but those plans did not materialize as Trump openly discussed his intention to endorse Vance.

CORRECTION (April 14, 2022, 6:13 p.m. ET): A previous version of this article misrepresented Rep. Jim Jordan’s involvement in the Ohio Senate GOP primary. He remains neutral; he didn’t endorse Josh Mandel.