When Robert F. Kennedy Jr.’s Cabinet nomination was still pending on Capitol Hill, Republican Sen. Bill Cassidy said he wasn’t sure how to vote on his confirmation. The Louisianan came around, however, after he received some private assurances from the longtime conspiracy theorist and anti-vaccine activist.

In remarks delivered on the Senate floor in early February, Cassidy — a physician prior to his political career — told his colleagues that if Kennedy was confirmed, the Centers for Disease Control and Prevention “will not remove statements on their website pointing out that vaccines do not cause autism.”

Take a wild guess what happened to the CDC website nine months later.

The Wall Street Journal reported:

A Centers for Disease Control and Prevention webpage that previously made the case that vaccines don’t cause autism now says they might. … The revised webpage says: ‘The claim “vaccines do not cause autism” is not an evidence-based claim because studies have not ruled out the possibility that infant vaccines cause autism. Studies supporting a link have been ignored by health authorities.’

In related news, the claim “the Tooth Fairy does not actually take lost baby teeth from under pillows” is not an evidence-based claim because studies have not ruled out the possibility that magical beings are secretly thieving teeth in the dead of night.

All joking aside, a little critical thinking goes along way. There is no evidence connecting vaccines and autism. Kennedy and his allies have invested an enormous amount of time and energy trying to uncover proof to substantiate their meritless claims, and they’ve failed.

The CDC, under the direction of the nation’s unqualified health secretary, has changed the information it shares with the public to promote an idea that flunks Logic 101.

Demetre Daskalakis, who formerly led the agency’s center responsible for respiratory viruses and immunizations, told The Washington Post that the online revisions show that the “CDC cannot currently be trusted as a scientific voice.”

Quite right. The change to the website is important in its own right, but more important still is the systemic damage that Kennedy and his team are doing to federal agencies and public health resources.

In recent months, it’s become common to see reports that quote CDC insiders who refer to the agency in the past tense. The New York Times published a report in late August with a headline and subhead that immediately generated some attention: “Will the C.D.C. Survive? Robert F. Kennedy Jr.’s assault may have dealt lasting damage to the agency, experts fear, with harsh consequences for public health.”

A day later, former CDC Director Dr. Tom Frieden appeared on MS NOW and told viewers, “I never thought I would see the day when you couldn’t trust what’s on the CDC website, but that day has come.”

That was soon followed by a New York Times op-ed co-authored by Frieden and several others who had held the same office. NBC News reported:

Health and Human Services Secretary Robert F. Kennedy Jr.’s leadership is ‘unlike anything our country has ever experienced,’ nine former directors and acting directors of the Centers for Disease Control and Prevention wrote in a scathing guest essay Monday for The New York Times. … Their tenures date to the late 1970s and span Democratic and Republican administrations, including Trump’s first term.

The mere existence of the opinion piece is itself notable: There is no precedent for nine former CDC chiefs — including Anne Schuchat, who served as an acting director during Donald Trump’s first term — linking arms to alert the public to a public health menace like this.

But just as notable, if not more so, is the condemnation itself. Under a headline that read, “We Ran the C.D.C.: Kennedy Is Endangering Every American’s Health,” the nonet was unreserved in its criticisms of the anti-vaccine conspiracy theorist who is currently serving as the nation’s health secretary.

“Mr. Kennedy has fired thousands of federal health workers and severely weakened programs designed to protect Americans from cancer, heart attacks, strokes, lead poisoning, injury, violence and more,” they wrote. “Amid the largest measles outbreak in the United States in a generation, he’s focused on unproven treatments while downplaying vaccines. He canceled investments in promising medical research that will leave us ill prepared for future health emergencies. He replaced experts on federal health advisory committees with unqualified individuals who share his dangerous and unscientific views. He announced the end of U.S. support for global vaccination programs that protect millions of children and keep Americans safe, citing flawed research and making inaccurate statements. And he championed federal legislation that will cause millions of people with health insurance through Medicaid to lose their coverage.”

Eleven weeks later, conditions are worse, not better.

As unsettling as these developments have been, none of what’s transpired at the CDC or the Department of Health and Human Services this year is surprising. Kennedy’s anti-science reputation was well established long before Trump nominated him. That an unqualified, anti-vaccine conspiracy theorist is behaving like an unqualified, anti-vaccine conspiracy theorist was painfully predictable.

The fact remains, however, that 52 Senate Republicans were given an opportunity to protect Americans from Kennedy — and they failed spectacularly. The more steps that Kennedy takes to put people at risk, the more GOP senators bear responsibility for his radical and dangerous decisions.

This post updates our related earlier coverage.

This article was originally published on MSNBC.com