One school of thought holds that the Obama Administration should investigate the violations of America's moral code that occurred under President Bush's watch: the torturing, the extraordinary renditions, Abu Ghraib, the whole Guantanamo charade. It would be like South Africa's Truth and Reconciliation Commission.
Punish those responsible (read here Cheney, Rummy, and lesser-known figures) so that those who might ponder these acts in the future would know that they couldn't get away with it. Also, prosecution would reaffirm to ourselves what we stand for as a nation.
Another school says let's move on, we have far more pressing problems to face down without getting mired in the sins of the past. Besides, it must have worked, because we didn't get hit again after 9/11.
President Obama, as is his wont, would like to split the difference: indulge in a little garbage-picking after we've addressed the immediate stuff. A pragmatic solution, although my gut says we should hold the malfeasance up to the light, and go wherever an investigation takes us. The national guilt we might feel for turning a blind eye to the dilution of our principles might inoculate us against falling prey to such apathy in the future.