Was Commuting Libby an Impeachable Offense?

Truthout:
Like a thief in the night, George W. Bush commuted the prison sentence of I. Lewis "Scooter" Libby. He made no public appearance to announce the decision, but instead air-mailed a written statement after 5 p.m. at the outset of a midweek holiday. The statement praised Patrick Fitzgerald as "a highly qualified, professional prosecutor who carried out his responsibilities as charged." As for Libby himself, the statement noted that "the consequences of his felony conviction on his former life as a lawyer, public servant, and private citizen will be long-lasting."