Photo: Camerique/Corbis

It was probably inevitable that the debate over the anti-vaccination movement would become politicized, given that we’ve now firmly entered the first stages of the 2016 presidential campaign, and given that nothing isn’t politicized in 2015. As the Times pointed out this week, some Republican candidates and potential candidates are dancing around the question of whether certain childhood vaccines should be required by the government, wary of alienating some parts of the GOP base. The paper also reported that in 2009 Rand Paul spoke to “a small physicians’ association that has publicized discredited medical theories, including possible links between vaccines and autism and between abortion and an increased risk of breast cancer.”

Pretty soon this could become a screaming match: Democrats will accuse Republicans of scientific ignorance; Republicans will accuse Democrats of allowing government officials, syringes in hand, to stand menacingly between parents and their kids. It’s a debate that, touching as it does on politically primal issues of government and liberty and rights and science, offers up exceedingly juicy red meat for both sides.

But it would be extremely unfortunate if this blossomed into a full-blown campaign issue. The research shows that those on the left are just as susceptible to anti-vaccine hysteria as those on the right — it is not, at the moment, an issue linked to political identity. But if the fight over vaccines becomes fully politicized, it will become linked to political identity, and there’s a great risk this could drive down vaccination rates.

At the moment, vaccination beliefs don’t map neatly onto any other big categories of political beliefs. “The people who have more mixed feelings about vaccines don’t sort cleanly along one variable in the way people often assume,” said Brendan Nyhan, a political scientist at Dartmouth who has studied both anti-vaccination beliefs specifically and political misinformation more generally. Rather, they consist of “different ideologies and religious and racial backgrounds. It’s a very diverse group.”

That doesn’t mean there aren’t easy stereotypes, of course. Perhaps the most frequently disseminated one is of a certain type of brainless, organic-food-obsessed liberal. “People have a mental model of the non-vaccinator and overgeneralize from that one stereotype they have in mind,” said Nyhan. “Rich liberals in Boulder, Colorado, Marin, California, and Santa Monica, places like that.” On the other side of the coin, liberals point at libertarians who put other kids at risk for the sake of their “liberty,” and at religious communities where an understanding of science is, to say the least, lacking.

Those hoping to score points off of these stereotypes have no shortage of fodder. “There certainly are places — rich, overwhelmingly white, educated coastal enclaves — that have high exemption rates in some of their schools,” said Nyhan. But on the other hand, he pointed out, Idaho — “not a liberal coastal enclave” — has one of the highest state-level vaccination-exemption rates in the country. And the biggest outbreak contributing to 2014’s uptick in measles cases, Nyhan said, was among the Amish population in Ohio. Orthodox populations in Brooklyn have seen outbreaks as well.

Simply put, liberals and conservatives appear to be approximately equally likely to contract anti-vaccination fever, at least if Nyhan’s research is any indication. Certain beliefs, like global-warming denialism, have a strong connection to political identity — in that case, right-wing political identity — but anti-vaccination beliefs are different. Dan Kahan, a law and psychology professor at Yale who studies belief formation and change, explained that people with strongly anti-vaccine beliefs are outliers when it comes to just about every demographic or ideological characteristic — they appear to formulate the belief and then build an ideologically tinged story around it. “Almost anybody who has a position is going to connect it to other positions they have,” said Dan Kahan. “Take someone like Robert Kennedy Jr., who supposedly thinks vaccines are dangerous. He’s going to connect it to populist themes, but that doesn’t mean that populist themes cohere to anti-vaccine views, in general.” At the other end of the spectrum, said Kahan, “There’s probably some religious fundamentalist person who’s going to be anti-vaccine; I’m sure that person connects it to his or her views.”

The fact that people with anti-vaccine beliefs are spread across the ideological spectrum is actually a good sign: As both Kahan and Nyhan pointed out, if anti-vaccination beliefs had taken hold among any one sizable group and changed that group’s vaccination behavior, we’d likely be faced with significantly lower vaccination rates — and a significantly scarier public-health problem — than what we’re seeing today. For whatever reason, American minds — conservative and liberal alike — seem relatively well-inoculated against anti-vaccine hysteria.

At the moment they do, at least. The worst-case scenario, as campaign season ramps up, is that this fight becomes politicized and sweeps moderately anti-vaccine folks — those who have developed misplaced fears about the process but are likely, at the end of the day, to go ahead and inoculate their kids — into the more radical anti-vaccine camp. “If you create the association between vaccines and identities in these groups, then you will make vaccination and vaccines [into this] very political conflict that doesn’t exist now,” said Kahan. Reams of social-science research have shown that when people feel their identity is under attack, their hearts harden, in a sense — they cling tighter to their group’s beliefs.

“If we turn vaccines into an us-versus-them debate, we might think we’re only arguing with those hard-core anti-vaccine folks,” said Nyhan. “But other people might take cues from that debate and say, I’m part of the ‘them.’ I’m more like the people who are being attacked. Or: They’re dismissing those people’s concerns just like they dismissed my concerns.” This, according to Kahan, would be very bad news: “That kind of cultural finger-pointing — that’s a kind of disease that threatens public health just as much as the diseases do themselves.”

So if this isn’t going to be a political issue, how should it be addressed? The expert consensus at the moment seems to be: (1) Researchers haven’t yet figured out which messages can bring anti-vaccine folks into the fold; and (2) to the extent any messages are effective, they have to come from local, trusted figures rather than dictates issued on high from politicians or national-level health authorities like the CDC.

Pediatricians are one example. “We know, based on several studies now, that parents really look to their children’s pediatric adviser for important influence on their decision-making,” said Douglas Opel, a pediatrician at Seattle Children’s Hospital who is developing a protocol to better gauge parents’ vaccination intentions. “There’s a lot of reasons to try to optimize those relationships.”

Kahan and Nyhan echoed similar themes — and both said that the number of hard-core anti-vaccination True Believers is actually quite low. The Jenny McCarthys of the world are greatly outnumbered by those aforementioned moderates — folks who, perhaps thanks to the ease with which people can access medical quackery these days, are a bit torn on the issue, but who, if approached the right way, might be willing to embrace the overwhelming medical consensus.

“The right way,” in this case, means in the quiet of a pediatrician’s office — not amidst the cacophony of a screamingly recriminatory national debate.

Jen Kirby contributed reporting.