LOL. No way will McCain attack Kerry. The best response we could hope for is no comment, but McCain can't keep his trap closed if a camera or microphone is nearby. It wouldn't surprise me if Kerry contacts McCain and asks him for more support re the new ad.
Isn't there a quote somewhere from McC where he says Kerry's words were used against him and his fellow POWs as well? I seem to recall this, but can't be sure. I know some enterprising FReeper has this saved somewhere. We may need to remind the MSM, in the event McCain goes the "no comment" route.