Measles is back and spreading, hurting kids, and invading Disneyland. Likely Republican presidential contenders Chris Christie and Rand Paul took some heat this week for comments regarding vaccination.

We can run down the long list of powerful politicians and influential celebrities who have uttered dumb thoughts about vaccines in America. Barack Obama, Hillary Clinton, and John McCain have flirted with autism-vaccine wackiness, so this isn’t an inherently partisan issue. And when you consider Hollywood’s roster of vocal anti-vaxxers, a few names quickly jump to mind:

Jenny McCarthy, Jim Carrey, Charlie Sheen, Bill Maher, Billy Corgan, Mayim Bialik, Alicia Silverstone.

McCarthy and Carrey have been hated on plenty for their part in this, and deservedly so. So why should Oprah Winfrey get a pass?

Who doesn’t love Oprah? America loves Oprah. The president loves Oprah. Everybody who has ever wanted a free Pontiac definitely loves Oprah. And yet the celebrated talk-show host, actress, and political player has a piss-poor track record when it comes to science.

In fairness, Oprah is no anti-vaxxer. She has, however, given one of the movement’s biggest celebrity mouthpieces a national platform. After actress and Playboy Playmate Jenny McCarthy launched her crusade—which included a Green Our Vaccines march and rally in Washington, D.C. in the summer of 2008—Oprah invited her on to her show.

“You’re mother warriors is what you are,” Oprah said in 2007, praising McCarthy and other moms dedicated to fighting autism. McCarthy’s son was diagnosed with the disorder, and she became convinced that vaccines had something to do with it.

“What number will it take for people just to start listening to what the mothers of children who have seen autism have been saying for years, which is, ‘We vaccinated our baby and something happened,’” McCarthy said during a fawning, sympathetic portrait on The Oprah Winfrey Show.

“Right before [my son’s] MMR shot, I said to the doctor, ‘I have a very bad feeling about this shot. This is the autism shot, isn’t it?’ And he said, ‘No, that is ridiculous. It is a mother’s desperate attempt to blame something,’ and he swore at me, and then the nurse gave [Evan] the shot. And I remember going, ‘Oh, God, I hope he’s right.’ And soon thereafter—boom—the soul’s gone from his eyes.”

McCarthy was allowed to spout this, pushback-free, to Oprah’s massive and adoring audience. (Oprah’s immense popularity and influence was the foundation for a cultural force that was dubbed “the Oprah Effect.”)

This should go without saying, but there is absolutely no evidence that vaccines cause autism. Zero. Nothing. None. And yet McCarthy soldiered on, with Jim Carrey at her side, much to the annoyance of professionals and onlookers who don’t want to see kids suffer needlessly.

The Oprah-McCarthy love fest didn’t stop there. In 2009, Oprah signed McCarthy to a development deal. This started with a slot on Oprah’s website, and led to chatter that a syndicated talk show, created with Oprah’s Harpo Studios, was imminent. The reaction to this wasn’t all that positive. “Why is Oprah Winfrey promoting vaccine skeptic Jenny McCarthy?” Slate asked, in a piece that noted Oprah’s spokesman insisting that McCarthy’s views were more “nuanced” than people give her credit for. “I knew that Oprah Winfrey was prone to antiscience… But now she’s gone way, way too far,” Phil Plait raged. “Oprah joins list of celebs enabling Jenny McCarthy’s conspiracy crusade,” Gawker sneered.

Fortunately, McCarthy dropped out of the production deal with Harpo Studios in 2011. But she did later get to take her brand and her views to ABC’s daytime talk show The View.

Oprah Winfrey never told parents to avoid vaccination like the plague. But she did serve as an enthusiastic megaphone for one of the nation’s most visible and reckless voices on the subject. And given Oprah’s reach, stature, and media empire, that kind of elevation certainly is not nothing.