President Trump’s political influence faces a critical test Friday when the Ohio Republican Party votes to formally endorse Rep. Jim Renacci, his handpicked choice to challenge Democratic Sen. Sherrod Brown in November.

The outcome isn’t assured. Mike Gibbons, a wealthy first-time candidate, has been wooing grassroots Republicans for months, winning the endorsements of four county parties. He hoped to emerge as the presumptive nominee after Ohio Treasurer Josh Mandel unexpectedly withdrew, but the GOP establishment, led by Trump, recruited and backed Renacci.

“Gibbons’ time investment on the ground is not to be ignored,” a Republican strategist active in Ohio told the Washington Examiner, on condition of anonymity in order to speak candidly and not run afoul of the White House. “Renacci — I bet he’s got his work cut out for him on this vote.”

The filing deadline to run for office in Ohio closed on Wednesday, about 12 weeks ahead of the May 8 primary.

Renacci has some catching up to do after shifting from the race for the Republican nomination for governor, where he was languishing, to the Senate race. His campaign spent its first month gathering petitions to meet the state’s filing requirements.

The fourth-term congressman earned millions before entering politics and is expected to partially self-fund his Senate campaign, although not as generously as Gibbons. Renacci, 59, and Gibbons, in his mid-60s, both lack name identification, and have to compete with Brown’s affable blue collar persona and $10 million war chest.

Renacci this week traveled with Trump to Cincinnati on Air Force One, joining the president for an event to promote the federal tax overhaul during which he made abundantly clear that the congressman has the White House seal of approval.

The Renacci campaign is confident the episode generated the support the congressman needed to win the Ohio Republican Party’s endorsement at Friday’s scheduled vote by the state central committee. Gibbons backers tracking the committee members claim that at least as of Tuesday, Renacci didn’t have the votes.

“While I don’t know the vote count, I suspect Jim Renacci almost certainly has the votes,” a central committee member who supports the congressman said Wednesday.

“I don’t know what the tally is going to be Friday, but I’d be shocked if Renacci isn’t overwhelmingly endorsed,” added a Republican strategist with Ohio ties.

This isn’t the first time Trump has thrown his weight around in Ohio, a state he won convincingly in 2016 and where his job approval ratings have held up better than his national numbers. Just before Trump’s inauguration, he personally lobbied the state Republican Party’s central committee to support his choice for state party chairman.

The move was the difference-maker in Jane Timken’s victory over Matt Borges, the preference of Gov. John Kasich, a Trump rival. Trump’s success in influencing primary contests has been mixed, however. His pick for the GOP nomination last year in a special election for Senate in Alabama was defeated.

That sets up an interesting race between Gibbons and Renacci — should Gibbons spurn the requests of senior Republicans in Washington to exit the race, as he has so far. “Every call he gets, he’s becoming more determined,” asserted a party insider who spoke with Gibbons recently.

The key, say GOP insiders, is whether Gibbons is ultimately willing to spend some of his personal fortune, as he has vowed to do.

“It’s not like if it was Mandel versus Gibbons; Mandel had run three times statewide, and he was popular with grassroots. Gibbons didn’t have a chance. But against Renacci? We’ll see,” a veteran Ohio Republican operative said. “With Gibbons, I’ve been pretty impressed with what they’ve been able to do on [the] ground. If he has resources, let's see. How much will [the] White House get involved in [the] primary?”

Both candidates are embracing Trump and running as his emissary.

Renacci is a wealthy businessman who professes frustration with Washington, and of course, he has the president’s endorsement. Gibbons is running as Trump’s true heir apparent — a wealthy businessman who supports term limits and joined the president last summer in criticizing Senate Majority Leader Mitch McConnell, R-Ky., when the two were feuding.

Going after McConnell didn’t help Gibbons’ standing with GOP leadership, especially since Trump and McConnell have since mended their relationship.

But his campaign believes it can use that fact to burnish its outsider credentials, just as Trump used opposition against him from establishment quarters for advantage in the presidential race. He’s likely to take the same approach if Renacci wins the state party’s endorsement.

Renacci has hurdles of his own to overcome. McConnell was hardly overwhelmed by him, first trying to recruit author J.D. Vance into the Senate race before settling on the congressman. His reserved personality is described as less appealing on the stump, although he is probably the more doctrinaire conservative, which could matter in a primary.