The number one thing that sunk Kerry, imo, was "I voted for it before I voted against it." Second was his anti-war record. 3rd was his blatant lying. 4th was his hideous wife. I could go on.
Don't forget his loser running mate "silk pony" along with his low-class wife!
You knew Kerry was an abysmal candidate when the Democrats basically admitted that he needed a Republican on his ticket in order to win in November.
The number one thing that sunk Kerry was running against a moral president who took a stand on what he believed.
That and the Democrats fielding a sitting senator against an incumbent president. It has never been successful before, why would it work this time?