WASHINGTON, D.C. — After months of lobbying from most of the candidates involved, former President Donald Trump endorsed J.D. Vance in Ohio’s closely watched U.S. Senate race this past weekend.

But the four other Republicans running against Vance have pledged to keep their campaigns alive through the May 3 primary.

Vance, a venture capitalist who gained fame for his memoir ‘Hillbilly Elegy,’ is already out with a new TV ad touting Trump’s support.

“J.D. Vance. Marine. Author of Hillbilly Elegy. President Trump’s endorsed America First conservative,” a narrator says during the 30-second spot released on Monday.

Last Friday evening, the former president released a lengthy statement saying Vance is “the candidate most qualified and ready to win” and that, although Vance was fiercely critical of Trump in 2016, “he gets it now.”

Justin Buchler, a political science professor at Case Western Reserve University in Ohio, called Trump’s choice slightly surprising, but pointed out Vance has used his Senate campaign to apologize publicly for once being anti-Trump.

“One of the things that Trump does appear to like is when candidates try to cozy up to him later,” Buchler told Spectrum News.

Trump’s decision is a big loss for fellow GOP candidates Josh Mandel, Mike Gibbons and Jane Timken. Throughout the last year, they each spent millions of dollars, visited Florida multiple times, and tailored their messaging on the campaign trail to earn Trump’s support.

But they each released statements Friday, making clear they plan to stay in the race until Primary Day on May 3.

State Sen. Matt Dolan, the lone Republican who hasn’t campaigned for Trump’s backing, also said he’s not going anywhere.

“If you have so many candidates that the vote will be split a lot of different ways, it’s easy for one candidate to say ‘All it takes is a few votes to shift and I win,’” Buchler said.

Trump will hold a rally in central Ohio’s Delaware County on Saturday.

His endorsement of Vance came right as the candidates had to release their fundraising numbers for the last three months. They show an incredibly expensive race that is being fueled by campaign donations, Super PACs and self-funding.

Democratic candidate Tim Ryan raised the most from supporters in the first quarter — $4 million. Mandel was the only Republican to raise more than $1 million in donations.

On the self-funding end, Gibbons and Dolan lead the pack, having poured $16 million and $10 million of their fortunes into their campaigns. Only Mandel, Ryan and Democrat Morgan Harper have put none of their own money into the race.

TV and radio ads continue to blanket the airwaves as well. The ad tracking firm Medium Buying said Monday that ad spending in the primary has exceeded $53 million.