From a New York Times news article headlined "Biden Faults Trump Over Schools' Inability To Reopen" (a story in which the word "teachers union" does not appear):
In response to a question, Mr. Biden also offered more details about how a mask mandate, something he has previously advocated, would work in practice — and what the limitations might be.
"I'm a constitutionalist," Mr. Biden said. "You can't do things the Constitution doesn't allow you the power to do."
Well, that is interesting and encouraging. Whether it matches his record as a senator and vice president is a different story. But if Biden keeps talking like that he might win.