There are a couple of new books about the FBI, and here is what I learned. J. Edgar Hoover's secret surveillance programs were explicitly ordered or approved by the President, including FDR and Kennedy. Hoover was a homosexual or cross-dresser. The FBI spied on M. L. King because because his top Jewish advisor was a Communist. Hoover cut off Sen. Joe McCarthy from info because Pres. Eisenhower regarded McCarthy as a political threat. The Watergate scandal was largely the result of the deputy FBI director vindictively sabotaging Pres. Nixon by illegal leaking slanted info from investigations.
Commies and commie sympathizers have always hated Hoover's FBI. If he really had presidential authorization for all of his investigations, then any blame should be on FDR, Kennedy, and the other presidents, not Hoover.