The Two Libby Theories

Matt lays them out:

The bottom line is that on one theory -- Libby broke the law to spare his superiors embarrassing revelations of their lawbreaking, and is being pardoned by those same superiors to help perpetuate the cover-up of their embarrassing lawbreaking -- Libby deserves to go to jail and Bush has seriously abused his power by pardoning Libby. On Nyhan's alternative theory -- Libby broke the law to spare his superiors embarrassing revelations of their embarrassing non-criminal conduct, and is being pardoned by those same superiors to help perpetuate the cover-up of their embarrassing non-criminal conduct -- Libby also deserves to go to jail and Bush has also seriously abused his power by pardoning Libby.

Yeah, that's about it. Still no clue here how Fitzgerald was "politically motivated."