(WASHINGTON) -- As the midterm primary season approaches, several Republicans running for state or national office are either refusing to disclose their COVID-19 vaccination status or advertising that they haven't received a shot, even as former President Donald Trump calls on his followers to get the vaccine.
Some experts say that disconnect could expose cracks in a party that continues to grapple with its loyalty to Trump as well as a growing distrust of government, scientists and the media -- and may signal a loosening of Trump's grip on the Republican voting base, according to Sarah Isgur, a former spokesperson for the Justice Department during the Trump administration.
"There's been an assumption within the political class that these are 'Trump voters,' implying that the former president himself can dictate their political support for or against a given candidate," said Isgur, who is also an ABC News contributor. "But the vaccine issue demonstrates the limits of that idea."
After denigrating many of the measures promoted by scientists to help curb the spread of COVID-19 during his time in office, Trump has emerged as an unlikely champion of vaccines. His promotion of the shot as "something that works" belies polling that shows unvaccinated adults are more than three times as likely to be Republicans than Democrats.
Trump has at least twice been booed by supporters for promoting the vaccine -- once at an August rally in Alabama and again in December when he told an audience that he'd received a booster shot.
"Don't, don't, don't," Trump told dissenters who booed the vaccine at the December event.
"If you don't want to take it, you shouldn't be forced to take it -- no mandates," said Trump, whose administration oversaw the speedy development of the vaccine. "But take credit, because we saved tens of millions of lives. Take credit. Don't let them take that away from you."
Critics of Trump, however, accuse him of paving the way for widespread vaccine hesitancy by undermining scientists in his own administration who advocated for masks and social distancing in the early months of the pandemic.
Now, several Republican candidates running under the Trump banner -- including some who have already earned his endorsement -- are parroting anti-vax rhetoric in their campaigns. Others are trying to toe the line by refusing to share their vaccination status altogether -- a position Trump has characterized as "gutless."
"Trump empowered this anti-vax monster, and now even he can't control it," said former Rep. Barbara Comstock, R-Va.
Former NFL running back Herschel Walker, who earned Trump's endorsement for U.S. Senate in Georgia, has declined to say whether he has been vaccinated. The early frontrunner in Ohio's GOP primary for U.S. Senate, Josh Mandel, has aligned himself with Trump but recently implied that he has not been vaccinated. And Florida Gov. Ron DeSantis, a longtime Trump ally, has dodged questions about whether he's received a booster shot.
In Arizona, a gaggle of Trump-backed and Trump-aligned candidates have been more explicit in their opposition to vaccines. Former television anchor Kari Lake, who Trump endorsed in the state's gubernatorial primary, said recently that she has "enough concern about the vaccine" to not take it.
Justin Olson, a candidate for U.S. Senate in Arizona, also said this month that he has not been vaccinated -- calling his decision "an issue of rebellion against" the Biden administration's vaccine mandates. And Sen. Ron Johnson, R-Wisc., enthusiastically accepted Trump's endorsement for reelection, even as he continues to stoke anti-vaccine fears.
A number of Trump-aligned candidates have cast their vaccine status as a matter of privacy. Arizona Attorney General Mark Brnovich, who is also running for U.S. Senate, has mocked reporters who have questioned him about it.
"My health information is my own information," Brnovich said. "Have you had an STD? I mean, seriously, if we're going to start asking about people's health information."
There's already evidence that opacity could be a winning strategy. In Virginia's recent election for lieutenant governor, Winsome Sears, a fierce Trump loyalist, refused to disclose her vaccination status, leading her Democratic opponent, Hala Ayala, to try to make it a major campaign issue.
"I encourage everyone to get the vaccine but no one should be forced to disclose their vaccination status," Sears wrote in a tweet ahead of election day. She then won the race.
Sears' triumph could be a sign that voters simply don't care if public servants are vaccinated. But it could also indicate the evolving relationship between Trump and members of his base, many of whom Isgur says are "disaffected and angry" -- even if some of that anger is directed toward Trump himself.
"It's why Trump's disapproval of a candidate has been so much more effective than his endorsement," Isgur said. "These voters are on the hunt for enemies, and they are just as willing to turn on Trump as anyone else."
Copyright © 2022, ABC Audio. All rights reserved.