Tara Haelle is a freelance science journalist who also blogs at Red Wine & Apple Sauce. She has a forthcoming book on evidence-based parenting and can be followed at @tarahaelle.

The dust appears to be settling after a couple politicians stepped into the national discussion about vaccination last week—and that’s something anyone who cares about public health should be cheering.

It started when New Jersey governor and potential 2016 presidential candidate Chris Christie told reporters in Cambridge, England, after touring a lab at vaccine manufacturer MedImmune, that the government should “balance” parental choice about vaccines and the interest of public health.


Then Sen. Rand Paul, another potential 2016 presidential contender and an ophthalmologist, saw an opening and quickly shared what he appeared to regard as the libertarian view on parents’ right to choose whether to vaccinate their children (a right parents already have, actually). Except, Paul took it a step further when he said in two television interviews that there have been “many tragic cases of walking, talking normal children who wound up with profound mental disorders after vaccines.”

He never said what mental disorders he was referring to—even if he was referring to autism, it’s more accurately described as a developmental disability than a “ mental disorder,” and those vaccine concerns have been long debunked—but his comments poured gasoline on the firestorm Christie had ignited.

The backlash, in the midst of the current measles outbreak, was swift and harsh, leading both politicians to do some serious backpedalling. Christie’s office issued a statement clarifying, “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.”

Paul took it a step further and tweeted a photo of himself as he received his hepatitis A booster shot.

But what led either one of them to step into the fray in the first place? If this was part of some political strategy on the part of either politician, then it doesn’t appear to be a well-considered one, experts have said.

“I don’t know why Christie would say something like that. What element is he trying to appease?” says Dan Kahan, a Yale professor who has studied how individuals make decisions based on in-group cues, including political cues. “If you look at the Republican Party and who doesn’t vaccinate, it’s not a very big group. It’s not an issue. If there is someone he’s appealing to, then I’m worried.”

He is not the only one concerned about what will happen if vaccines enter the realm of national political debate. Paul’s comments in particular called up the specter of Michelle Bachmann’s Republican presidential debate gaffe when she claimed the HPV vaccine can cause mental retardation ( no, it can’t). If vaccines become politicized, that makes it harder for public health officials and medical providers to talk to the public about vaccines’ safety and effectiveness.

“The goal is to protect Americans and get more people vaccinated, not win a political fight,” says Greg Dworkin, M.D., chief of Pediatric Pulmonology and Medical Director of the Pediatric Inpatient Unit at Danbury Hospital in Danbury, Connecticut, and a writer at Daily Kos. He pointed out that vaccination rates are uniformly high among families of both Democrats and Republicans, well past 90 percent for most vaccines. “Who wants it 50-50 because the parties take sides? How would that help anyone?”

Indeed, it wouldn’t, says Kahan. Even former First Lady Rosalynn Carter sounded a warning not to politicize vaccination.

“When issues become entangled in group identities and become symbols of membership and loyalty to those groups, people genuinely aren’t as able to recognize and assess the evidence as they otherwise would be,” Kahan says. In a series of studies, Kahan and others have shown that when people are asked to make decisions about an issue that lacks an ideological association, the study participants can adequately assess the evidence they are provided. They don’t have a vested interest in a particular outcome. But when the issue is an already politically charged one—such as gun control—or if the researchers manipulate a situation to attach political ideology to a decision, people become less able to parse the evidence. “Those kinds of tribal affiliations are going to get in the way of our ability to perceive the information in a way that reliably connects our judgments to what the science is,” Kahan says. “Anything that provokes those dynamics is going to be a form of science communication pollution,” examples of which Kahan has literally mapped on his blog.

So far, his research shows that discussions about vaccines have not become a left-right issue. When the news of Paul’s comments broke, even bastion of libertarian journalism Reason Magazine openly asked, et tu, Rand Paul? After all, Reason has previously published strong arguments in favor of requiring parents to vaccinate, suggesting that Oliver Wendell Holmes’ quote that “The right to swing my fist ends where the other man’s nose begins” includes the microbes in that nose. That’s not to say the question on mandatory vaccinations is not divisive among some libertarians— it is—but that’s the point: Feelings about vaccination simply do not line up along any political divisions.

“Vaccines aren’t a partisan issue. The consensus in favor of vaccination in this country is very strong and extends across every religious, racial and political group,” says Brendan Nyhan, an assistant professor of government at Dartmouth College, who has studied the way individuals assess information about vaccination. “There’s no reason it should be otherwise—communicable diseases don’t care what party you support.”

Indeed, a skim of other political contenders for 2016 reveals that the vast majority support vaccinating children against diseases. Senate Majority Leader Mitch McConnell, though not a presidential contender, was quick to say he’s a “ big fan of vaccinations“ considering he was a victim of polio. And neither Christie’s nor Paul’s comments came close to those of a long-time anti-vaccine crusader who couldn’t come from a more liberal political dynasty, Robert F. Kennedy Jr.

If anything, the question of mandatory vaccination splits along generational lines rather than political ones. A recent Pew Research survey found that 41 percent of 18 to 29-year-olds believe vaccinating children should be up to the parents, compared to only 20 percent of adults over age 65—also those most likely to have lived through outbreaks of the diseases children now avoid with vaccinations. Given that older adults are more likely to show up to the polls, that makes Christie’s and Paul’s statements appear even more off-base.

More concerning than the idea that Christie or Paul was pandering to a particular subsection of voters, however, it the idea that they may have been testing the water in making vaccination a wedge issue, Kahan suggested.

“The other thing that scares me is that they have an interest in making this an issue when it isn’t,” Kahan says. “Conflict entrepreneurs know if they can get other people to fight with them, they’ve won. If others see it’s ‘us vs. them,’ that’s the only information that counts. The actual content of the conversation doesn’t matter.”

It does appear that Paul has a history associated with anti-vaccine sentiment. As the New York Times and other outlets reported, his ties to Association of American Physicians and Surgeons, an organization of “libertarians in white coats,” as medical ethicist Art Caplan describes it, go back a ways, and the organization’s president has said she believes the science isn’t yet solid regarding risks from vaccines (though it actually is). As Michael Gerson at the Washington Post persuasively argues, Paul’s original statements about parental choice in vaccination are simply the latest in a long line of gaffes where he accidentally reveals his true beliefs before engaging damage control and trying to blend back into the mainstream.

But does that mean he has plans to make this a 2016 issue? Probably not.

“To be fair, both offices walked their statements back almost as soon as they hit the media. I think they realized the problem of not being firm on the need for vaccination, and also saw the almost immediate criticism of what they said,” Dworkin says. “In follow-up, both clearly said ‘get vaccinated, and then multiple candidates and leaders, a long list including Barack Obama, Jeb Bush, Ted Cruz, Marco Rubio, Bobby Jindal, John Boehner, Mitch McConnell, and Hillary Clinton, all publicly supported vaccinations. This mitigated the damage that could have occurred by making the consensus non-partisan.”

And that’s the way it needs to stay, according to Nyhan.

“If this story disappears in a day or two, it won’t change anything. The overall flow of messaging is what matters,” he says. “My concern is about the potential cumulative effect of treating vaccines as a partisan or political issue over time. What we don’t want to happen is for people to view vaccination as a political choice—either for liberals in certain coastal enclaves or Republican supporters of Chris Christie or Rand Paul.”

He doesn’t anticipate that happening in 2016.

“It almost certainly won’t be a general election issue, but it may rattle around in the primaries a bit,” he said. “They’re running for president, not surgeon general.”