Bernstein compares the current mess with the Nixon pardon and Iran-Contra. The crux of his argument:
[A]nother drawn-out legal process, like the one from 1987-1992, is likely to get the same results; Republicans will feel persecuted for partisan reasons, or at least claim that they feel that way, and between that and real legal jeopardy for so many people, they will rally around the torturers. Which will mean (and has meant) endorsing torture ever less grudgingly. Basically, I think that the goals of reviving the consensus against torture and of devising good procedures for dealing with terrorists are not compatible with the goal of prosecuting people.
I understand those who believe that there's a moral imperative involved in seeking justice for those who committed evil acts. I can't really argue against that. All I can do is to say that politics involves trade-offs, and in this case, if I'm right, satisfying the moral imperative will involve real costs that those who oppose torture, in my opinion, should be reluctant to accept.
As I've said, all of this would be especially true if George W. Bush himself would cooperate by accepting a pardon, admitting to what happened, and denouncing torture. With him (and certainly Powell, and probably Rice if Bush was in, and with those three probably quite a few others) on board, Cheney and his gang would really be isolated