Whether he defended a terrorist or not is irrelevant. Everyone has the right to an attorney, and a really good attorney is able to defend even the indefensible (even if they personally disagree with it). Second, this is a government attorney employed by the Department of Justice, obviously someone who will do what he is payed to do and not after his own ideals. Next, even terrorists have the right to be defended and have their side of the story heard. Murderers are represented on a daily basis because they are still humans who have basic human worth. Terrorists, although terrible in their morals and actions, have basic worth. Finally, just becuase he represented a terrorist has no implications on his ability to attack the Arizona law. He is merely the tool. The base argument that the DOJ put out there will still be argued, which is legitimate.