As
Digby pointed out, Clinton was tried by the Senate and acquitted. Once again, the "b-b-b-but Clinton!" defense is completely irrelevant and only used to try and divert attention from what's really going on.
When it comes to pardons and commuted sentences, Bush is the most
parsimonious President in history. At least that is consistent with his character, such as it is. Further, Bush's claim that he commuted Libby's sentence because it was "too harsh" is shown to be a lie by the fact that the sentencing was completely within the guidelines for the crimes Libby was convicted of
and the way the Bush administration has pushed the use of sentencing guidelines as mandatory and
absolute minimums.
Bush commuted Libby's sentence instead of pardoning him so that Libby would continue to enjoy 5
th Amendment protection for any testimony he might be called to do before Congress. Libby will be pardoned later, when the investigations are over and they don't see any further need to protect Cheney, Bush and Rove themselves. Failing that, you can bet that Bush won't pardon Libby at all, valuing his own skin far more than some lackey's and knowing that Libby will be well taken care of by the
wingnut welfare system.