A banner encouraging flu vaccines hangs outside a clinic in Hattiesburg, Mississippi. Nobody’s stopping to read it.
Republican healthcare mistrust has moved from fringe talking point to measurable public health crisis — and a new study published in Nature Human Behavior shows the gap between how liberals and conservatives engage with medicine is now wider than education, income, or geography can explain.
Neil O’Brian, a political science professor at UNC Chapel Hill, breaks the phenomenon into two phases. Phase one started in the 2010s, when education polarization began sorting Americans by degree status — college-educated voters drifted left, non-college voters drifted right. Since education predicts health outcomes, the gap made a certain statistical sense.
Phase two started during COVID-19, and the numbers stopped making sense.
“This is a real puzzle,” O’Brian said. “We turn to the survey data and show that people on the right are less likely to trust, engage, or use medicines to treat chronic illness relative to the left.”
Translation: Republicans aren’t just skipping COVID boosters. They’re skipping blood pressure meds. They’re avoiding annual checkups. They’re walking around with untreated hypertension — the leading risk factor for cardiovascular disease, which kills more Americans than anything else.
The Vaccine Conversation Went Sideways
Past research showed Republicans died from COVID-19 at higher rates than Democrats, largely due to lower vaccination rates. But O’Brian’s study reveals something darker — vaccination rates alone don’t explain the health gap. The issue is systemic mistrust of the entire medical apparatus.
Jay Van Bavel, a psychology professor at NYU who studies polarization and health, sees the trend accelerating under the second Trump administration. “When you elevate someone like RFK Jr to oversee health decisions for the country, now you’re getting all of these things entrenched and embedded in national health policies around vaccination.”
RFK Jr — now one of the highest health authorities in government — continues to insist that “the government actually lies to us” about health. The irony of a government official undermining government credibility isn’t lost on Van Bavel: “They don’t seem to understand how that undercuts their own authority.”
The anti-vaccine conversation, once narrowly focused on COVID shots, has metastasized. Measles vaccines — proven, essential, uncontroversial for decades — are now suspect. Red states are striking down vaccine mandates. The fringe became the platform.
Mental Gymnastics at Scale
Van Bavel points out the contradictions embedded in the movement: people refuse vaccines because they don’t want “unknown chemicals” in their bodies, then seek out ivermectin — an unproven COVID treatment with zero regulatory blessing — without hesitation.
“There is this stream of populism that’s anti-elite and anti-authority that exists in both parties, but is very strong on the right and is really part of the identity of the Trump administration,” Van Bavel said.
The result? Republicans are more likely to suffer from long COVID — because they were less likely to get vaccinated — but also less likely to seek treatment or even acknowledge the diagnosis. The feedback loop tightens.
Hypertension, Untreated
O’Brian’s research shows conservatives now report higher rates of hypertension than liberals — but are simultaneously less likely to visit a doctor, less likely to trust medical advice, and less likely to believe blood pressure medications are safe or effective.
Cardiovascular disease is the number one killer in the United States. Untreated hypertension is a ticking time bomb. The math is brutal.
“If lots of people walk around with untreated hypertension, that’s really bad for the individual and for public health,” O’Brian said.
The Data Gap
One reason this trend went unnoticed for so long is that most large-scale health surveys don’t ask about politics. The National Longitudinal Study of Adolescent to Adult Health — which O’Brian’s team relied on — is one of the few exceptions.
“One of the things that makes it remarkable for me as a political scientist is that it’s really the only study that does ask about people’s political beliefs,” O’Brian said.
Without tracking political affiliation alongside health outcomes, researchers can’t see the pattern — and policymakers can’t address it. O’Brian argues that needs to change, fast.
What Happens Next
The health gap widened during COVID. It’s widening still. Red states are dismantling vaccine mandates. RFK Jr is setting national health policy. Trust in doctors — among a significant chunk of the population — is collapsing.
Van Bavel sees the trajectory clearly: “What we’re seeing is a continuation and expansion of a lot of the dynamics that happened during the pandemic.”
The clinic in Hattiesburg still has its flu vaccine banner up. The question is whether anyone’s walking through the door.
Source: The Guardian