These 'we want to but we can't' arguments bother me more and more as i grow older. It's usually a pretty transparent excuse for not doing the right thing, by scared old men or ambitious young men.
Tossing one tenured professor out is a simple thing. After all like you said, it's not written down in the constitution.
The problem with removing tenure is that it destroys trust in the tenure system. If one professor is stripped of tenure for being controversial, then no one is safe. For this reason the only way to lose tenure is to do something illegal, since that's really the only line you can draw that doesn't move very much.
Tenure is an all or nothing deal. The entire effect of protecting your faculty is completely nullified as soon as you violate your principle for one guy. The floodgates open and suddenly every prof that's doing something controversial becomes a target.
We haven't invested much energy recently in creating institutions that have adequate defenses against this kind of threat model. Our assumption has been that the socialization structure either produces people who are pathologically criminal or are socially responsible. The emergence of a class of social behavior which is "respectable" and despicable at the same time is a threat we need to deal with.
Except you can't - because he didn't violate international nor domestic law. He never waterboarded anyone, nor did he order the waterboarding of anyone.
He worked on legal justifications for the use of torture, which is not an area of international law that's well defined. He didn't make policy nor law, he spun law so that it fit existing policy.
I won't disagree that what he has done is despicable, but what exactly would you charge him with that would actually stick?
Just for the record, if you're a victim of one of these released prisoners, it would be more serious for you than simply bad press.
Is the man in the article lying then? He says he's innocent. Of course he would. But who are you to decide one or the other?
Of course not. But, is you looking bad in the media worth someone else's human dignity? That's a much easier sell.
I understand that it looks bad if people released from custody in Gitmo return to action in 'violent non-state actor' groups. But is looking bad in the media worth human dignity? There's a reason that US citizens have rights like due process (and you can see why everyone should get them, including Gitmo prisoners): If you can't prove it but refuse to let the defendant maintain the freedom that should be associated with presumption of innocence, you get incarceration of the type described in the original posting.