My Guess? The Nixon Mask Was Inside Out.

 Sometimes youtube's suggestions algorithm absolutely nails it. There was no way I wasn't going to click on a video called Bob Newhart & the Masked Doctor Who Cured the Gays. Although a possible inspiration for The Texas Chainsaw Massacre's Leatherface, this masked doctor in question is the far more benign John E. Fryer, M.D., a closeted member of the American Pyschological Association at a time when homosexuality was listed as a mental illness. In 1972 he was persuaded to finally propose its delisting at the annual meeting of the APA in a speech entitled "I Am A Homosexual", which he delivered on the condition that he was allowed to do so in disguise.

 

 "Dr H. Anonymous" to the left of the campaigners who convinced him to make this address: Barbara Gittings and Frank Kameny. (Source).
 

  Fryer wore a velvet tuxedo, a large curly wig, and what was reported to be a mask of Richard Nixon, and the "Cure" of the video's title is the subsequent delisting of homosexuality as a mental illness in 1973. That "&" is doing quite a but of heavy lifting, but Bob Newhart was the star of a popular sitcom at the time about a psychiatrist, which in 1976 decided it too should probably take a stand. Since the recommendation of this video I've been for a delightfully deep dive into Matt Baume's channel and it's interesting to note how much more progressive television shows seem in the seventies than in the decade that follows, despite the continuity of creative teams behind them. Things don't always slowly get fairer then. Often they get fairer, then get pushed back. But I don't want to bang on about the eighties.