He knew, but didn't say it out loud, that J. Edgar Hoover was a queer, and while he was, he was squandering the time of the American people.  And yet, America was dumb enough to leave him in his job for 47 years.  That's kinda unprecedented except today would be heralded as "righteous".  NOT BY ME.  The man was a crook on top of everything else!

https://rollingout.com/2011/11/28/j-edgar-hoover-of-the-fbi-was-both-black-and-gay-historians-speak-out/

"President Harry Truman saw the FBI as the seed of a totalitarian cancer it would later become."  He was totally correct, too.  Like I said, Truman knew......

J. Edgar Hoover was a monster, on top of everything else he was.  He should never have been allowed to rise to the position he had, obviously he was also a good actor which is why people didn't SEE him for what he truly was.  A MONSTER.