If there was any doubt that politics, not science, is driving the Centers for Disease Control and Prevention’s coronavirus guidance, newly released emails between the CDC and a powerful teachers union should settle the question once and for all.

The emails, obtained through the Freedom of Information Act by watchdog group Americans for Public Trust, show that President Joe Biden’s CDC tightened its masking guidance after the National Education Association threatened to criticize the administration publicly. The correspondence followed the CDC’s May 13 announcement that fully vaccinated people no longer needed to wear masks indoors or outdoors. The NEA responded in an email to the White House and demanded that the CDC clarify that masks should still be worn by both adults and children in schools at all times. If this clarification was not made, the NEA threatened to publish this critical statement: