I wonder if anyone has ever thought the reason Kennedy bashes Bush so much is that he sees the family dynasty (or so perceived dynasty) being eclipsed by the Bushes (Bush 41, Bush 43, Jeb...) that he is just trying to make everyone think back to the days of JFK and the esteem many in the country felt about them.
If you ask me, he needs to shut his pie hole and drink himself to an early retirement. The country would be better off for it and the Kennedy name would just fade away...
I think you've nailed it!