- JD Vance's win in Ohio is a signal that Trump's sway over the GOP's base remains unshaken.
- Vance clinched a win over rival Josh Mandel in the GOP's race despite trailing in polls in March.
- Vance is one of many Trump-backed candidates who have found success in the GOP's primaries.
Republican JD Vance's primary win in Ohio displayed the power of a highly sought-after Trump endorsement in moving the needle on vital GOP races.
On Tuesday, Vance was declared the winner in Ohio's Republican primary with 32% of the vote, clinching the nomination to run as the GOP candidate for an Ohio Senate seat over rival Josh Mandel.
Vance's clinching the nomination was also widely viewed by analysts as a good measure of whether Trump's backing of a candidate still matters and the extent to which the former president still affects Republican voters.
In March, Vance was trailing in the polls with warnings — even from a super-PAC supporting him — of what seemed to be an impending loss. But Vance quickly moved up in the polls after a clutch Trump endorsement.
Local officials urged Trump not to endorse Vance, encouraging him to pick another candidate in the race. Trump himself suffered some blowback from the Vance endorsement, even among his diehard right-wing base, particularly in light of how he seemed to overlook Vance's previous comments about him.
Vance has a well-documented history of criticizing Trump. In one exchange with his former college roommate, Vance said he thought Trump could be "America's Hitler."
Vance's win appears to indicate that Trump's backing matters.
"MAGA is alive and well, and the GOP best take notice and finally understand where the people are," tweeted Donald Trump Jr., the president's son, after Vance's win.
"Anybody who dismisses Donald Trump as not a major factor in the party is crazy," Dave Carney, a veteran national Republican consultant, told NBC News.
"When Trump endorsed Vance, on April 15, Vance was third at about 10%, behind Mandel and Gibbons each at 21%," tweeted political commentator Bill Kristol, the director of advocacy organization Defending Democracy Together.
"Without Trump's endorsement, Vance almost certainly stalls out at 10% and finishes fourth. When Trump talks, Republicans listen," Kristol added.
Trump has recently endorsed what the GOP might view as risky candidates like Vance and Dr. Mehmet Oz, with advisers fearing that a high-profile loss of a desired Trump candidate would call into his question his image as the Republican kingmaker.
The former president has not shied away from doling out endorsements. According to Ballotpedia, Trump has made 160 endorsements since leaving office.
However, some of the candidates he's backed have struggled in their races, like Georgia gubernatorial candidate David Perdue and Alabama Senate hopeful Rep. Mo Brooks. Trump, however, rescinded his endorsement of Brooks when the congressman began flagging in his Senate bid, saying he "went woke."
The former president has also claimed credit for high-profile wins by GOP figures, including Glenn Youngkin's gubernatorial victory in Virginia. Youngkin did not campaign with Trump and seemed to keep his distance from the former president. However, that didn't stop Trump from endorsing Youngkin and crediting his November win to "MAGA voters."
Vance is now slated to face off against Democratic candidate Tim Ryan. Both are seeking to replace GOP Sen. Rob Portman, who is retiring from office.