(NewsNation) — Ohio’s primary election will be the first test of the strength of former President Donald Trump’s midterm candidate endorsements, including Senate hopeful, venture capitalist and conservative commentator J.D. Vance.

Voters across the U.S. have begun weighing the candidates Trump elevated to pursue a vision of a Republican party steeped in hardline populism, culture wars, and denial of his loss in the 2020 campaign. The former commander in chief has been vocal during the crucial election year as he is expected to make another presidential bid in 2024.

One of Trump’s high-profile endorsements is “Hillbilly Elegy” author Vance, who is running for an open U.S. Senate seat in Ohio. Seven candidates are on the ballot in Tuesday’s Republican faceoff for the coveted seat of retiring Republican Rob Portman.

Vance will face off against former Ohio Treasurer Josh Mandel, Cleveland investment banker Mike Gibbons, former Ohio Republican Chair Jane Timken, state Sen. Matt Dolan, whose family owns the Cleveland Guardians baseball team, and entrepreneurs Mark Pukita and Neil Patel.

Vance is riding high on the Trump endorsement, while other candidates who campaigned on their loyalty to the former president are banking on heavy ad spending and a strong ground game to help them win. 

“If J.D. Vance wins, it’s going to be considered the tipping point, that’s for sure,” Decision Desk HQ adviser Scott Tranter said.

Vance’s opponents frequently bring up his past criticism of Trump during Trump’s 2016 presidential bid. The former president has appeared to move past Vance’s past criticism publicly.

“Like some others, J.D. Vance may have said some not-so-great things about me in the past, but he gets it now, and I have seen that in spades,” Trump said in a statement after he endorsed him. “He is our best chance for victory in what could be a very tough race.”

In the coming weeks, primaries in Nebraska, Pennsylvania and North Carolina will also serve as a referendum on Trump’s ability to shape the future of the GOP.

Former Republican New Jersey Gov. Chris Christie said last month that Trump’s endorsements aren’t the end-all-be-all of the midterm elections.

“It will always be a factor because the former president has influence inside the party, but I don’t believe his endorsements will be determinative,” Christie told ABC’s “This Week” anchor George Stephanopoulos.

But political reporter Julia Manchester told “Rush Hour” Tuesday that Ohio’s primaries will be the true test.

“This will be a test of his political power going into 2022. It will show how in tune he is with the Republican base,” Manchester said.

“Whichever way it swings could determine the majority of the Senate and which way the Senate leans,” Manchester continued.

On Sunday, Trump, while speaking in Greenwood, Nebraska, fumbled on Vance’s name, mixing it up with the former Ohio treasurer running against him. Vance told CBS News Monday that he was unconcerned by the slip.

“He gives, what, thousands of words of speeches every single week,” Vance told CBS News. “Sometimes he’s going to misspeak. Everybody’s going to do that.”

Associated Press and The Hill contributed to this report.