In 1983, a scientist named Bill Foege resigned as the director of the Centers for Disease Control and Prevention.

He did so, Michael Lewis tells us in his new book, "The Premonition," because after CDC researchers had discovered a connection between aspirin and Reye's syndrome in children, the aspirin manufacturers complained to the White House. President Ronald Reagan's administration responded by telling the CDC to "cease and desist," according to Foege. So he quit.

Foege was a career CDC scientist — the last career agency employee to hold the title of director. Every director since then has been a political appointee — "plucked from the supporters of whichever politician happened to occupy the White House" — whom the president could fire at will. Thus did the CDC go from being an agency focused solely on science to one focused as much or more on politics.

As Lewis's book — and the pandemic — illustrates, this shift didn't just damage the CDC. It damaged the country.

A more recent example of this shift came to light last week, when the New York Post published an article detailing e-mails between the CDC and the American Federation of Teachers, which has been a strong supporter of President Joe Biden. The e-mails had been obtained by Americans for Public Trust, a conservative group that seeks, as it puts it, to hold "politicians and political groups accountable for corrupt and unethical behavior." After I read the Post article, I asked the group to send me the e-mails, which it did.

Maybe, when the CDC was purely about science, the exchange between the union and the federal agency would have been viewed as "unethical." Today, sadly, it is par for the course.

Some quick background: As you may recall, soon after Biden took office, the CDC was charged with publishing science-based guidance for reopening public schools safely. Because of the recalcitrance of the teachers unions, schools in most big cities were operating either entirely remotely or under a hybrid plan, even though study after study showed that children were far less likely than adults to either get or transmit COVID-19 and that classrooms were safer than just about any other place a kid could be. Three CDC researchers acknowledged as much in an article in the Journal of the American Medical Association.

The new director of the CDC was Rochelle Walensky, who had run the infectious disease department at Massachusetts General Hospital and taught at Harvard Medical School. Since the beginning of the pandemic, she had been one of those scientists the public had come to rely on for advice about mitigating COVID-19.

In early February, just two weeks after Walensky was confirmed by the Senate, she got her first taste of politics trumping science at the CDC. During a briefing with reporters, she said reopening schools did not necessarily require that teachers be vaccinated — something that real-world experience had long shown. The teachers unions, however, were adamant that teachers should be vaccinated before reentering the classroom. Walensky was quickly slapped down by White House press secretary Jen Psaki, who said the CDC chief was speaking "in her personal capacity" and that her remarks didn't constitute "official guidance."

Meanwhile, behind the scenes, Walensky was getting another political lesson. As the agency was putting together its school-reopening guidance, Randi Weingarten, the formidable head of the AFT, and Kelly Trautner, the union's health policy official, inserted themselves in the process.

"Thank you again for Friday's rich discussion about forthcoming CDC guidance and to your openness to the suggestions made by our president, Randi Weingarten, and the AFT," Trautner wrote on Feb. 1. "We are hopeful that lines of communication will remain open, and that we can serve as a true thought partner as you continue the important work towards safe reopening of schools." Trautner then offered "suggested language" regarding accommodations for "high-risk individuals."

On Feb. 11, just before the guidance was issued, Trautner sent an e-mail to Walensky and other CDC officials complaining that the guidance didn't contain "provisions providing for when schools should close." She added — with no intended irony — "We really want to lend our efforts to helping restore faith in the CDC."

When the guidance was published the next day, Weingarten and the AFT were thrilled. It called for social distancing of 6 feet between students, for making teacher vaccinations a priority and for schools to remain closed in high-transmission communities. It also included the language Trautner had suggested for high-risk individuals virtually word for word. Weingarten praised the agency for relying on "facts and evidence."

Critics pounced on the guidelines, saying that, rather than promoting reopening, they gave teachers new excuses to avoid returning to the classroom. Why, for instance, did students need to remain 6 feet apart, which made it nearly impossible for public schools to have a full complement of students in a classroom? Indeed, before joining the CDC, Walensky had said in a private e-mail that 3 feet was "quite safe."

A month later, the CDC updated its school guidance to "reflect the latest science on physical distance between students in classrooms." It concluded that 3 feet was just fine.

How did Weingarten respond? Not well. "We are not convinced that the evidence supports changing physical distancing requirements at this time," she said in a letter to Walensky. The CDC chief then sent a long letter back to the AFT aimed at roping them back in as allies. (It worked.)

But why should the CDC care whether Weingarten and the teachers are friend or foe? An agency that claims to "follow the science" should devise guidance that "calls it like it is," as Howard Cosell used to say, rather than how the president's supporters want it to be. The fact that it so transparently did the AFT's bidding is precisely why many people have lost faith in the CDC.

It's not just Trump who co-opted the agency; it's a process that has been going on for more than a quarter-century.

That perhaps explains why the CDC offered no apologies when its e-mail exchanges with the AFT were made public. A spokeswoman sent me a list of more than 50 organizations that had been consulted on the guidance.

"As part of long-standing best practices," she wrote, "CDC has traditionally engaged with organizations and groups that are impacted by guidance and recommendations issued by the agency."

Best practices?

As long as the CDC views consulting with the president's allies as appropriate — even when those allies possess no particular scientific knowledge — it will never regain the credibility that once made it so special.