Washington (AFP) - A series of bruising May primary contests will test Donald Trump's grip on the Republican Party as voters weigh his preferred candidates ahead of November's midterm elections, starting Tuesday in Ohio.
A dozen states are holding nominating contests, with a particularly brutal battle playing out on the Republican side among hardline right-wingers adopting the former president's scorched-earth campaign style.
Trump has made endorsements in most of the contests, making them a litmus test of his influence 18 months after being defeated by President Joe Biden, and of his prospects for another run at the White House in 2024.
Across the key battlegrounds of Ohio, Pennsylvania, North Carolina and Alabama, nearly four in ten Republican 2022 Senate primary ads mentioned Trump, according to an AdImpact analysis provided to Punchbowl News.
"The results of the primaries will test whether the Republican base is still the Trump base," Alexander Heffner, host of PBS's long-running "The Open Mind" and co-author of the forthcoming "A Documentary History of the United States," told AFP.
"If Trump-endorsed candidates do not perform favorably, the trajectory to the 2024 presidential nomination will appear different, with the potential for independent wings of the party to reemerge."
In Ohio, the former reality TV star picked bestselling author and venture capitalist J.D.Vance as he bids to be a Senate candidate in one of the most-watched races.
Vance, whose 2016 memoir "Hillbilly Elegy" became an Oscar-nominated Netflix movie, was plucked out by Trump over more popular rivals in a wide-open primary to replace retiring Republican Senator Rob Portman.
Political capital
Trump couldn't get Vance's name right at a rally in Nebraska on Sunday.
"We've endorsed J.P., right?J.D.Mandel," Trump said during the rally, confusing Vance with one of his competitors, Josh Mandel.
The former president's backing has nevertheless proved a huge boon for Vance, who once called his new patron "America's Hitler" but moved from obscurity in the race to a five-point lead after successfully courting Trump's endorsement.
While Ohio is on course to reaffirm Trump's role as Republican kingmaker, the 75-year-old has also banked much of his political capital in contests that hint at the limits of his post-presidential clout.
On May 17 the primary season takes in the crucial battleground state of Pennsylvania, which has generated headlines with a Trump-backed celebrity Senate candidate of its own.
Trump's support for Mehmet Oz -- known to his legion of fans on "The Oprah Winfrey Show" as Dr.Oz -- seems to have helped the TV surgeon leapfrog his closest rival, former Treasury official David McCormick.
But while Oz has built a small lead, the polling doesn't show him clearing the field with a Vance-sized bounce.
Bitter fight
The stakes are high in Georgia in November, a state which voted Democrat last time around but could change the balance of power in the Senate if it swings back Republican, with broad implications for Biden's presidency.
It is also the epicenter of Trump's election disinformation campaign and the increasingly bitter fight over voting rights.
Trump has repeatedly berated Republican Governor Brian Kemp for certifying the 2020 results, which the governor was required to do by law after Biden's victory in the former Republican stronghold.
In a direct appeal to Trump followers who continue wrongly to question the validity of the election, Trump-backed former senator David Perdue has made false claims about fraud a centerpiece of his campaign.
Yet Perdue's fortunes are markedly worse since Trump's endorsement, with the gap behind Kemp widening from seven points to a massive 25.
The clearest threat to Trump's kingmaker status has come in Alabama, where he enthusiastically backed congressman Mo Brooks, a prominent speaker during the January 2021 Washington rally where Trump fired up the mob that stormed the Capitol, for the Senate.
Trump revoked that endorsement in an embarrassing about-face last month, however, with Brooks trailing badly.
Brooks has since turned on Trump, claiming that the former president asked him to illegally "rescind" the results of the 2020 election and help remove Biden from office.
Author, journalist and political profiler Mark Leibovich believes reminding Republicans that Trump's winning streak is not all it is cracked up to be could be the best hope for more traditional Republicans to win their nomination races.
"The guy lost not only reelection, which is really difficult to do, he lost the Senate for Republicans, he lost the House for Republicans, the White House for Republicans," Leibovich told MSNBC in a weekend interview.
"He's the first Republican in 100 years to lose all three chambers in a single term."
