I say we should punish Bushists (the two mentioned above in particular) because they are stinking criminals, regardless of whether people of similar kind are deterred from performing similar actions. The hell with those criminals; but it is more important that we find a way to prevent such people from taking power in the first place, and I do not think that will be done by trying to make psychopaths think they could be punished. We are missing the problem and not addressing it head on.
(If we could cure stinking criminality with drugs and therapy, that would change things. Our ‘actual’ problems would become clearer.)