My political analysis is that the Republican moderates accepted the Bush would keep doing what he's doing for the next few years and once he's finally out of office the country would go back to its old ways. This is true to an extent, Israel has experimented with legal torture but recently has largely backed off on the matter. Even so, what the administration has done is already a permanent stain on America's reputation. The only consolidation at this point is that it hasn't been seconded by other branches. This would not only do that, but has provisions explicit to prevent punishment for prior acts.
As one of the other blogs I read pointed out, the other nasty result is that U.S. interrogators can now be expected by law to implement these procedures. That's substantially worse than a nebulous situation where the absence of congressional policy give more room to say no.
All in all, Congressional Democrats should fight this, with filibuster if necessary. It may end up costing us seats, but even if it costs us gaining the House it's worth it. Moral leadership sometimes requires taking hits. I'm quite troubled by the American public apparent ambivalence, at best, on this issue. But we aren't going to change those opinions if we don't fight this one.