February 5, 2015 6:39 AM EST

Measles ranks among the nastiest human viruses, able to hang in the air and lie low among entire unprotected populations. But never before has it spread around the world as it did on Feb. 2, jumping from an outbreak of unvaccinated kids in California’s Disneyland to the mouth of New Jersey Governor Chris Christie as he traveled in London.

“Mary Pat and I have had our children vaccinated, and we think that it’s an important part of being sure we protect their health and the public health,” he said after a question about the Disney outbreak. Then he added, “Parents need to have some measure of choice in things as well, so that’s the balance that the government has to decide.”

With that coded phrase–some measure of choice–the measles virus went viral once again, along with the age-old debate over parental rights, public health and government mandates. “The state doesn’t own your children,” Kentucky Senator Rand Paul, another likely Republican candidate for President, followed up on the subject of vaccines. “Most of them ought to be voluntary.”

Ever since Boston first required smallpox vaccination for schoolkids in 1827, public backlash has lingered as an antibody. Where some see a public health benefit, others see a needle or lance pushing foreign bodies into the bloodstreams of children. And so the fear gets filtered through our politics, with candidates sending code words–I’m on your side, Mom and Dad–to the skeptics on both ends of the political spectrum. In the 2008 presidential campaign, candidates John McCain and Barack Obama both entertained the notion that vaccines might have caused a spike in autism, a theory that had been discredited years before.

Today, all 50 states require schoolchildren to get a broad spectrum of vaccines, and both the science and law are settled. Specific religious or philosophical objections, the U.S. Supreme Court ruled as far back as 1944, do not give parents the right to avoid mandates imposed by the state. Vaccines, after all, are not just another seat-belt or helmet law, meant to protect an individual from an untimely end. They also protect others, by creating a herd immunity that stops bugs from coursing through populations, where they might target the most vulnerable, many of whom are unable to get vaccines on their own.

Yet the fear of government-mandated injections remains. In 1900, leafleters ranted against the “menace to personal liberty,” and that language is once again ascendant, from the Tea Party conclaves of the Deep South to the tony farmer’s markets of Hollywood. Lawmakers routinely introduce bills that would once again allow milk to be sold without pasteurization: liberty for dairy (and salmonella too). A debate over whether states should require a new vaccine for the human papillomavirus, a cause of cervical cancer, broke out during the 2012 presidential race, when then candidate Michele Bachmann wrongly claimed that it could cause mental retardation.

In a culture upended by diminished authorities, such fights will continue. But vaccines should fade as a campaign issue. Just as soon as Christie and Paul blew their dog whistles, party leaders from around the U.S. rose up to end the conversation. The mandated vaccines should be mandatory, they said, almost without exception. Soon after his remarks, Christie clarified his support for measles mandates, and even Paul, who once described mandatory vaccines as a step toward martial law, did what he could to raise a white flag–inviting a reporter from the New York Times to photograph him getting a booster shot during a doctor visit.

This appears in the February 16, 2015 issue of TIME.

More Must-Read Stories From TIME

Contact us at letters@time.com.

Read More From TIME
Related Stories
EDIT POST