War is not a nice business. If the U.S. had not been willing to violate the Geneva Conventions on some occasions when it proved necessary, we'd likely be speaking German.
It was a mistake in Algeria and it is a mistake in this one.
The war is not going to be won in an interrogation chamber, but out in the field on the one hand, and in the American political process on the other. Since the last is by far the weakest part, if makes no sense whatever to hand AlQ a defeatist dem president because you dislike McCain's stance on torture.
Furthermore, even if you were right about its expediency, it would still be a matter of conscience not a party-line whip vote, and to demand that McCain of all people sign off on such a policy is completely inhuman. If a catholic pol feels he has to dissent on a death penalty vote, we'd make allowances. We can't be charitable about a man who was tortured for five years straight, not being able to support it as a policy?