Because New Jersey Governor Chris Christie recently quarantined a nurse in a large tent when he thought she might have had Ebola, you might have assumed that he of all people would seize upon a measles outbreak—attributable to a movement of anti-vaccine reactionaries—to lecture parents for putting children at risk. But when pressed to take a position on the view that parents should vaccinate their children, Christie hedged. “It’s more important what you think as a parent than what you think as a public official,” he said. “I also understand that parents need to have some measure of choice in things as well. So that’s the balance that the government has to decide.”

It’s tempting to attribute his sudden fondness for "balance" to lessons he over-learned during the Ebola panic he helped nurture. But it's also mistaken.

Vaccine skeptics don’t mirror climate change deniers, who are overwhelmingly conservative and amplified by vast wealth. But the anti-vaxx movement nevertheless presents a greater political problem for Republicans than Democrats, who, like President Obama, are unafraid to make explicit declarations about the importance of vaccinating children. By and large, Republican politicians don’t tout their own ignorance of vaccine science or use it to shield themselves from substantive questions about immunology, public health, or child rearing. Vaccine skepticism and climate change denial are, again, more different as reactionary movements than they are alike.

But two facts about vaccine skeptics and the risks they pose make it difficult for Chris Christie and perhaps other Republicans to treat anti-vaxxers as brusquely as he’s happy to treat unionized teachers in Newark.

It’s not that Republicans must pretend to believe that vaccines cause autism. But a large, motivated population of vaccine skeptics begs for interventions Republicans can’t easily get behind. The two most straightforward ways to increase vaccination rates or otherwise reduce the risk of losing herd immunity are: Imposing government mandates and stigmatizing the white, affluent people who comprise the core of the anti-vaxx movement.

Hectoring white people and imposing mandates on their families doesn't fit comfortably in the GOP wheelhouse these days, and Christie's awkward walkback underscores the bind that places on conservatives exquisitely.

Christie's office: “The governor believes vaccines are an important public health protection and with a disease like measles there is no question kids should be vaccinated. At the same time different states require different degrees of vaccination, which is why he was calling for balance in which ones government should mandate.”

Shorter Christie: I am a scientist, man. But a conservative one.

Conservatives and liberals are both overwhelmingly of the view that childhood vaccines carry important benefits; conservatives, however, are inherently skeptical of government interventions of any kind. Thus, Republican politicians who lean too heavily on the state action, even in the realm of something as essential to the common good as immunization, will run into problems.

A 2014 study by Dan Kahan for Yale Law School’s Cultural Cognition Project found that people with left-leaning political outlooks are likelier to support restricting non-medical exemptions for childhood vaccine requirements, likely reflecting “an ideological predisposition against government regulation independent of any ideological sensibility specific to childhood vaccination.”

This tendency might not hold if anti-vaxxers existed on the fringes of political life, or were overwhelmingly of foreign origin, or were monolithically liberal. Opposition to government intervention can be both reflexive and selective. But the available evidence suggests vaccine skeptics tend to be white, educated, affluent, and, per Kahan's study, politically diverse.

It's not that Republicans are in thrall to vaccine skeptics, but it can be difficult for them to confront vaccine skeptics in ways that don’t alarm conservatives for other reasons. And taken to an extreme, it becomes hard to tell the difference between the two.