At first blush, I'm not sure I agree. I think Bush & Co. should attack Kerry immediately and point out that 4 months in Vietnam do not make you a leader, a conservative, or even a moderate. This guy has been AWOL for the last 30 years on national defense, which has been proven time and time again by his Senate record. One 45 minute speech doesn't change that.
I wouldn't touch JFK's Vietnam experience. It would only look petty and provides an obvious opening for the Dem attack dogs (who'll get plenty of media coverage -- remember that the playing field is far from level).
My advice: use *humor*, straight talk, specifics, and optimism.
The problem, though, with that, is that the Bush campaign has been attacking Kerry for the last several months. In fact, that has been the vast majority of their campaigning, has been attacking Kerry. They're already under fire for running such a negative campaign and swing voters are sure to feel alienated by such "politics of division," as the talking heads have repeated over and over. Most swing voters don't have an unfavorable opinion of either Bush or Kerry so if Bush can make a good case for why swing voters should vote for him, instead of against Kerry, I think he can do pretty well. Save the attacks for after the convention.