[This post had been updated]

Carly Fiorina believes parents should make the choice whether to vaccinate their children.

"When in doubt, it is always the parents' choice," Fiorina told a rural Iowa audience Thursday evening.

Later that night, she added that, "when you have highly communicable diseases where we have a vaccine that's proven, like measles or mumps, then I think a parent can make that choice." She added, though, that a "school district is well within their rights to say: 'I'm sorry, your child cannot then attend public school.'"

"So a parent has to make that trade-off," she told reporters, including The Washington Post's Jenna Johnson.

If recent GOP history is any guide, Fiorina might soon regret those comments and reverse course.

Just look what happened earlier this year when her fellow 2016 GOP contenders, New Jersey Gov. Chris Christie and Sen. Rand Paul (Ky.), made similar comments.

During a February measles outbreak in 14 states, Christie told an anti-vaccine supporter that he thinks parents "should have some measure of choice" in vaccines. Around that same time, Paul said, "I’ve heard many tragic cases of walking, talking normal children who wound up with profound mental disorders after vaccines."

Clarifications from both candidates soon followed.

Christie's spokesman said the candidate only meant there should be greater scrutiny on states' different levels of vaccination requirements, but that for "a disease like measles," there's "no question" children should be vaccinated.

Paul, an eye doctor, said he didn't intend to make a connection between mental disorders and vaccines:"I do think that vaccines are a good idea." He soon was pictured on Twitter getting a booster shot.

And a few months later, in April, Christie seemed to land on the other side of the issue, telling a woman in New Hampshire who was concerned about vaccines that, "You can't count on me for that. I would err on the side of protecting public health through vaccine unless that vaccine has proven to be harmful to the public."

What Christie and Paul realized is that siding with religious liberty when it comes to vaccines is a political pitfall. The science is decided on this: Vaccines save lives, and suggestions that they might cause things like autism are baseless. 

By contrast, tea party darling and acclaimed neurosurgeon Ben Carson avoided the vaccine trap during that measles outbreak. He said he thought vaccines and the role they play in public health is "extremely important in our society."

So the political science seems pretty decided on this issue too. Christie, Paul and Carson all calculated the political costs of questioning vaccines to please the very limited number of vaccine skeptics wasn't worth it.

Fiorina sought to cover herself by saying that schools could refuse vaccinated children. And that's certainly a key bit of nuance that she could emphasize if she is pressed on this issue. If unvaccinated children aren't in school, she could argue, the risk of communicable diseases spreading is less of an issue.

She could also note that many states have laws allowing for some degree of religious and philosophical exemptions from vaccines.

But she's already taking heat for her comments -- from fellow GOP 2016 contenders like George Pataki, the former New York governor:

If past is prologue, it's probably best Fiorina just drops this.

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