It was a plane crash, no? (Getting tinfoil hat ready...)
It is an interesting set of coincidences. JFK was the heir apparant to Monyhans Senate seat, and was looked at as a Presidential contender a few cycles down the road.
He dies in a plane crash. His recovered body is quickly cremated and the ashes buried at sea off the fantail of a USN destroyer retasked for just that purpose.
The Kennedys then throw all their support behind Obama in 2008, pretty much waging holy war against the Clintons like some kind of mafia vendetta.
Then again, JFK had a secretary named Lincoln and Lincoln a secretary named Kennedy. Both were killed on the same day of the week, in the presence of their wives, etc etc etc ...