Actually, attacking the President is probably Kerry's best strategy. It's not like Kerry can or would inspire anybody to vote for him.
A negative campaign in every sense. Voters will be sick of this by Election Day.
The Three Cs won't do it - Criticize, Condemn, and Complain. Leaders DO NOT practice The Three Cs.
The fact that in 20 years in the Senate he has failed to author any substantial legislation proves that he's not a leader.
Put some jam on 'im; he's toast.