As a U.S. senator and presidential candidate in 2008, Hillary Clinton expressed support for the theory that childhood vaccinations contribute to autism, writing in a campaign questionnaire that she was “committed” to finding the causes of autism, including “possible environmental causes like vaccines.”

Childhood vaccinations became a political issue on Monday after New Jersey Gov. Chris Christie was roundly criticized for telling reporters, “It’s more important what you think as a parent than what you think as a public official.”

“So that’s the balance that the government has to decide,” Christie continued, adding that, “Not every vaccine is created equal, and not every disease type is as great a public-health threat as others.”

The subject of childhood vaccinations and the activist groups who oppose the safeguard — so-called anti-vaxxers — has come to the fore amid an outbreak of measles in the U.S.

Christie’s stance on the issue took another twist after The Daily Beast reported on a letter Christie wrote to campaign supporters in 2009 in which he expressed sympathy for parents concerned by New Jersey’s “highest-in-the-nation vaccination rate.”

“I stand with them now, and will stand with them as their governor in their fight for greater parental involvement in vaccination decisions that affect their children,” Christie wrote.

Those comments were cited by many as problematic:

This @olivianuzzi article on Chris Christie’s suck-up to anti-vaxx parents hits like a punch to the face http://t.co/eQ3JstBVst — Tim Mak (@timkmak) February 2, 2015

Chris Christie, call your office. http://t.co/U6AWU3whaG — Chris Cillizza (@TheFix) February 2, 2015

But as a 2008 presidential contender, then-Sen. Hillary Clinton indicated that she was a vaccination skeptic as well.

As The Huffington Post and The American Prospect reported in April of that year, Clinton called for more research into the autism-vaccination link in response to a questionnaire from the group Advocates for Children’s Health Affected by Mercury Poisoning, or A-CHAMP.

Clinton wrote that she was “committed to make investments to find the causes of autism, including possible environmental causes like vaccines.”

And in response to the question of whether she would support more research into a link between vaccinations and autism rates, Clinton wrote: “Yes. We don’t know what, if any, kind of link there is between vaccines and autism – but we should find out.”

As was reported at the time, Clinton was joined in her skeptical views by then-Sen. Barack Obama and Sen. John McCain, the Republican nominee for president in 2008.

“We’ve seen just a skyrocketing autism rate. Some people are suspicious that it’s connected to the vaccines. This person included. The science right now is inconclusive, but we have to research it,” Obama said at a campaign rally in Pennsylvania in April 2008.

Later on Monday, Christie’s office clarified the comments he made in London:

“To be clear: 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.”

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