Psychology

If you parse the Kerry team statements with regard to Dean's comments on the recent terror alerts you'll see that they never really "disowned" him. They just said that they didn't want to go as far as Dean did. They never said that Dean was wrong or that he shouldn't have said what he said. they just said that they want to believe the President.

In other words, Kerry is putting himself into the position of being just like the rest of America. Which means that when the rest of America feels betrayed they will look for affirmation of their feeling of betrayal by looking to the guy standing next to them and ... it will be John Kerry.