I'm possibly one of the few liberals who agrees with President Bush that "the prison sentence given to Mr. Libby is excessive." Two and a half years in prison is a lot of time for a non-violent crime. The problem is not Bush's decision to commute Libby's sentence; it's his failure to take similar action for the federal inmates serving still longer sentences for nonviolent offenses, especially drug offenses. It's also not obvious that Libby should do no time at all. In other words, Bush may have been right (inconsistency aside) to reduce Libby's prison time but wrong to reduce it to zero.
Of course there's another dimension to this case: the suspicion that the Libby commutation was a reward for his keeping the administration's secrets (thus far and into the future). But for that offense, Libby was only ever going to be the fall guy.