You guys can support whatever you’d like. Torture is illegal no matter who you do it to. There are two questions here: 1. Is waterboarding torture? 2. Were there mitigating circumstances? Amnesty’s position on the first is clearly that it is (and they’re not American, so I’m not sure where the idea of trying them for sedition comes from, nor can I imagine that anyone here thinks it’s illegal to say pretty much whatever you want about the president so long as you don’t threaten him physical harm). As for the second, usually that would be a matter for the courts.
Amnesty would hypocrites if they didn’t think Bush should be prosecuted here, since they would think anyone else should be.