If I recall correctly, the Bush regime did not want to follow through with a full 9/11 investigation, and their Senate proteges have been stalling on the investigation of WMD (un)intelligence (despite the way that the Democrats have until recently been playing Milquetoast; why didn’t the GOP rush through a report before the Democrats drank their morning double espresso?). They’ve been stalling Plamegate investigations and Abu Ghraib investigations.
But once word gets out that the CIA may be maintaining secret prisons, now that needs an investigation, fast. Not the secret prisons, of course — the fact that somebody found out.
Of course they never torture anyone, so please don’t pass that bill making it explicitly illegal to torture people.