A four-week stretch of primaries, including the pivotal May 17 election in Pennsylvania, will challenge the clout of former President Donald Trump’s support for GOP candidates.

Tomorrow, the Ohio primary kicks things off with J.D. Vance, author of Hillbilly Elegy, surging to the front of the Republican Senate race, thanks in part to the endorsement of Trump.

Vance has picked up 12 points since the 45th president gave his blessing and a victory would, as POLITICO stated, “remind his party that Trump is still king.”

A win by either former state treasurer Josh Mandel or investment banker Mike Gibbons would shift the dynamic and sound alarm bells for Mehmet Oz, who secured the Trump endorsement in the Keystone State Senate race.

“It’ll be a blow to his perceived power,” said John Thomas, a Republican strategist who works on House campaigns across the country. “He doesn’t single-handedly control the electorate unless he’s on the ballot. Is he still a very, very popular figure in the Republican Party? Absolutely, undeniably. But does he have the influence and weight in Republican primaries to be the decisive kingmaker? … Not definitively.”

The endorsement has changed the strategy for Pennsylvania Republicans candidates. Dave McCormick, one of six other challengers for the nomination, has launched a campaign showing voters who support Trump, but not his pick of Oz.

“Trump made a mistake on this one,” says a character in one of the spots.

“Oz gets the endorsement, and I get the benefit,” said conservative commentator Kathy Barnette. “Why is that? Because name ID works both ways. Oz’s name ID is so high that we all know he’s not a conservative.”

“In Pennsylvania, the Republican Senate primary is still in flux,” said Christopher Nicholas, a GOP consultant to POLITICO. “I think the Trump endorsement would have had more oomph had it happened in February than mid-April.”

“President Trump’s support has had a big impact and I’m excited about getting our message out over the final two weeks of the campaign,” said Oz.

Dates To Watch

• May 10 – Nebraska and West Virginia
• May 17 – Idaho and Pennsylvania
• May 24 – Georgia

It does not look like a mistake was made with two Senate selections, that of Rep. Ted Budd in North Carolina and former football player Herschel Walker in Georgia, as both have comfortable leads. 

But other state races in Nebraska, West Virginia, Idaho and Georgia – as well as Pennsylvania – will keep a focus right where Trump likes it – on himself.

“Is Trump an important figure in the party? Yes,” said Ryan Horn, a Republican media strategist. “Is he the only figure in the party? No, and my guess is that we’ll see that.”

And by the end of May, we may know the direction of the GOP headed into not only November, but 2024 as well.

“You’ve got a faction that wants to pull the party way to the right, and you’ve got a faction that wants to moderate it, and who wins, I don’t know,” said Phillip Stephens, a state GOP executive committee member in North Carolina.