Glenn Greenwald on the Bill Moyers Journal had this to say: "What happens if you allow serious law breaking to go unpunished is you're telling political leaders, current and future, that there's no need for you to abide by the law. There's no reason for you to consider yourself constrained or limited in what you do. Because even if you commit crimes while in office, we're going to be too afraid of creating divisiveness... And the damage that comes from that is infinitely worse than whatever this divisiveness is that so many people are afraid of when citing why we should let these criminals go free."
However, in spite of the lack of political will on the part of the Democrats, we cannot possibly undo the damage that has been done without holding the Bush administration accountable for its actions. The damage that would be done by not holding them accountable would be much worse than whatever controversy is stirred up by establishing an independent investigation and prosecuting those who believed they were above the law and acted on that belief.
It's entirely possible to appoint an independent, nonpartisan investigator to bring to light the crimes that have been committed. That's not to say that there won't be those who would try to politicize the process anyway. But the actions of the investigation can and should be above politics and above reproach.
If we don't hold the Bush administration accountable, there's absolutely nothing that will prevent future leaders from believing that they also are above the law. It's an invitation to tyranny.
If we're really against torture, extraordinary rendition, warrantless surveillance, the undoing of habeas corpus, the establishment of the "unitary executive" (read: king), then we must act. If we don't, it will be clear to the world, to our children, and to our future leaders that we really don't have the courage of our convictions when it comes to the rule of law, we really don't care if they chew up our rights and civil liberties and spit them out.
We absolutely cannot afford to let this slide. Nothing less than the future of freedom is at stake.