No, of course it’s no surprise that the Bush Administration acts like a criminal conspiracy. The interesting question is what precise testimony Libby could have offered against Cheney or Bush if he’d actually been facing prison time. Congress should find out. At this point, there’s no reason not to bring Libby in, immunize him, and start asking questions. His Congressional testimony wouldn’t be relevant to his appeal. It might prevent a retrial should the DC Circuit reverse his conviction. So what?
After Libby, let’s hear from Cheney. Since he’s not a part of the Executive Branch, surely he can’t claim executive privilege. And if the inquiry is into Cheney’s own impeachment, I doubt the courts would interfere.