He (or his equally cynical entourage) then realized what an enormous source of votes jumping on the Civil Rights bandwagon could be. The Civil Rights parade was quite a way down the street when Marilyn's boyfriends started marching.
Also, most "assassination experts" inexplicably overlook LHO's sojourn in the USSR, seeming to completely buy the KGB story that they "had no interest" in him, which they floated via a series of defectors whose genuine-ness is still the subject of controversy. The internecine warfare over this point wrecked the CIA's effectiveness for quite a while
Me? I think Fidel was in it up to his eyeballs. I seriously consider the possibility that Fidel promised Carlos Marcello and Santo Traficante a better deal than the Kennedys and the CIA. Maybe payback for the Kennedy Brothers trying to bump him off.
Still doesn't solve anything, but it is true that the CIA had been penetrated by the DGI, the Cuban Intelligence Agency, which, although it generally is under everyone's radar, is right up there with the CIA and Mossad in the high level of professionalism in its activities.