I'll wager Kash N. Kerry will be preaching about how such a strike would not have been made unless the Iraq war happened. It's all Bush's fault.
He will conveniently forget 9/11 (no Iraq war then), or the Kenya bombings, or WTC 93, or....
John Kerry has already said if an attack happens, its Bush's fault for not doing enough. HE (Kerry) would do more to prevent attacks, like strengthen intelligence gathering and ties with the UN and foreign governments.
In Spain the reaction was panic and cowardice, "if we elect a different government, then we won't get in trouble like this again" In its essence, this reaction was also a complaint that the present government did not do enough to stop terrorism.
All Bush can do in this kind of attack is to show us every day that he is doing everything possible, and if he isn't (like at the borders) he is vulnerable to this criticism.
I don't believe Kerry will do more in any case, the other attack Bush can make is to show Kerry is a liar and soft on terrorism. He has to do at least one, and could just as easily do both.