” IIRC, some government source (FBI?) had let her listen to recordings of MLK”
That would have been Bill Moyers, LBJ’s press secretary, followed by a PBS career. Robert Novak said that Moyers had been letting people listen to tapes from FBI wiretaps.
Yes, the source very likely was Bill Moyers. By the early ‘80s, though, that liberal/left hypocrite apparently had amnesia, recasting himself as an unabashed MLKjr fan and saying that he couldn’t remember much about the material dug up on King in the ‘60s.
As Barry Goldwater once said about Moyers, “Every time I see him, I get sick to my stomach and want to throw up.”