By Alexandra Ulmer and Jarrett Renshaw

(Reuters) – Donald Trump’s political clout will be tested in May, when candidates he endorsed are running for Republican primaries. This is the beginning of November’s congressional midterm elections.

Trump-backed North Carolina, Ohio and Pennsylvania candidates face well-funded and active challengers for the Republican nomination to serve as U.S. Senate. Trump angered by his rejection of his fraudulent claims that Trump’s 2020 defeat in the election was due to fraud, Trump also supported a Georgia Republican governor challenger.

These are the most prominent — and, in the case for the Senate, the most crucial — candidates among more than 150 for local, federal and state elections Trump has supported this year. The races of these candidates will be carefully scrutinized to see if there are any signs Trump’s grip on his party is slipping as he considers running for president in 2024.

Mike DuHaime, Republican strategist and advisor, stated that Trump’s endorsement was still very powerful but that it is not invincible.

Trump’s controversial Senate picks Herschel Walker (ex-football star in Georgia) and Mehmet Oz (Pennsylvania television doctor), won victories in May. But, these wins would not ensure success in the Nov.8 general elections. Democrats may be able to retain their razor-thin Senate majority by making mistakes.

According to polls, at least one Trump pick in May is J.D. Vance of Ohio leads going into the Tuesday primary. Oz trailed rival David McCormick(NYSE:) in the Pennsylvania May 17 primary, while former Senator David Perdue was ahead of Georgia Governor Brian Kemp as they head into their May 24-matchup.

Trump-backed candidate’s poor performance may not decrease his support among his core supporters. Reuters/Ipsos polling showed 83% Republicans viewed the ex-president favorably. 40% also said he represents their party the best, well ahead the 25% of his closest potential opponent, Florida Governor Ron DeSantis.

Justin Sayfie from Ballard Partners, an Orlando-based lobbying company with connections to Trump said “His power base tens of million of disaffected voter around the country.” “Regardless of what happens with his endorse candidates, I do not think that it will alter the fact that he would remain frontrunner for the GOP Nomination for 2024.

According to sources, Trump should finalize a Midterms Spending Plan for his large war fund following the elections in Ohio and Pennsylvania.

Trump’s spokesperson did not respond when asked.

TRUMP’S CANDIDATES

On April 15, Trump shocked Ohio Republicans by supporting Vance on behalf of them. Vance is a Venture Capitalist and Author who had been harshly critical about the president in the past.

Trump had received letters from more than 40 Republican officials urging him not to endorse Vance. They argued that Vance’s past of criticism of Trump would make him a good candidate for president.

A Fox News poll found that Vance had risen 12 percentage points over a prior poll, to earn the support of 23 percent of primary voters. His opponent, Josh Mandel, lost 2 points, to poll at 18%. However, 25% of the voters remain undecided.

Trump’s April 9 endorsement for Oz in Pennsylvania hasn’t done much to change the polls. McCormick is the most recent survey and McCormick was the closest.

A Monmouth University survey released this week found that 61% Pennsylvania Republicans said they would vote for McCormick, compared with 51% who voted for Oz.

North Carolina polls indicate that Trump-backed Senate candidate Senator Ted Budd is leading former Governor Pat McCrory. But, there could be a July runoff due to the crowded field.

Trump in Georgia defied Republican establishment and encouraged Perdue, the incumbent popular in Georgia to challenge Kemp. Trump then infuriated Kemp by certifiying the 2020 election results which showed that President Joe Biden won the state.

Perdue lagged Kemp by some 20 points in a recent poll published by the Atlanta Journal-Constitution.

“Georgia will be the proving grounds for what the remainder of the country will see: It is time to turn it page,” declared Lieutenant Governor Geoff Duncan (an anti-Trump Republican).

Trump seems to doubt Perdue’s ability to fulfill his promises. Trump said to Perdue at a March Georgia rally: “I hope David you’re going be governor.” Or, I wasted an awful lot of time tonight.”