Kennedy was a plagerizing womanizing guy who dated such women as Judith Exner Mob Boss Girlfriend and an eastern block spy while he was President. The guy appears to have been every bit as much a sex-addict as Bill Clinton, his worshiper. We now find he was high on medications most of his Presidency, if not all. I wouldn't doubt we'll find the same thing about Clinton in time.
Carter was an unmitigated disaster when it comes to foreign policy. I doubt anyone could have done more serious damage to global stability and western values in just four years.
Clinton? I think we know about Clinton.
The point is, this is what the Democrats have given us in the last fifty years. Frankly it's amazing they still have any party memebers left.