He'll run, but he won't spoil anything. John Kerry and the Democrats voting for him in the primaries right now are doing a good enough job of spoiling it for themselves.
Kerry is the Democrat Rove and Co wanted all along. They were preparing for him for a good 2 years until Howard Dean came along. They've meticulously planned every and any possible angle to attack the man, and they'll succeed. I hope Kerry fights back, and I think he will. But despite his best efforts, the discipline and ruthlessness of the President's campaign war machine will be too strong.
I'll vote for the man, but I'll hold my nose while doing it.