Remember the whole JFK-Camelot bullish**? Remember how the Kennedy clan was untouchable?
Now even on PBS one can see documentaries that openly speculation that Marilyn Monroe was murdered, the most infamous of Kennedy's affairs, talk about Joe Sr's connection to the mafia. Ted's lechery is now admitted by all. Only possible 50 years afterwards as you point out when everyone's dead and they have lost their power. Same will occur with Obama - if anyone even cares about that lightweight by then.
Many are fervently praying the truth will be known much sooner. I believe our prayers will be answered.