One can look at it the other way.
Take the Rita ruling recently decided by the SC and cited in the article. The facts of the case in some fashion mirror those of the Libby trial, and the Sentencing Blog link can be followed to get some background. The ruling held that appellate judges can UPHOLD as 'reasonable' a sentence -- as here -- w/i the guidelines. The Bush Administration, again that blog and others dicuss the pt, supported this move.
A strict on crime Bush appointment handed down a ruling here after the case was tried by a Republican prosecutor. This is perfectly consistent to the ideal 'hard on crime' mentality many support, not just those who voted for Bush. It is inconsistent for Bush to selectively say it is "excessive" when quite normally the same general facts (Rita also involved someone in public service -- a vet -- perjury as a result of an investigation, etc. ... "excessive" in his eyes? apparently not) are handled differently.
One should also underline the inconsistent use of the pardon power. One sees this concern by conservative leaning sorts like those at Volokh Conspiracy:
Nonetheless, I find Bush's action very troubling because of the obvious special treatment Libby received. President Bush has set a remarkable record in the last 6+ years for essentially never exercising his powers to commute sentences or pardon those in jail. His handful of pardons have been almost all symbolic gestures involving cases decades old, sometimes for people who are long dead. Come to think of it, I don't know if Bush has ever actually used his powers to get one single person out of jail even one day early. If there are such cases, they are certainly few and far between. So Libby's treatment was very special indeed.
It is interesting to suggest that the issue here is WHO decides what is "excessive," not the "excessive" nature of the situation in particular. I'm not sure if it really works on the facts though.
-j