A good pick is someone who successfully forwards your ideology through the deepest bowels of government. Someone who is so simpatico with you that they understand what you want even better than you do, and so cutthroat that they will do whatever needs to be done to enact your agenda, even if it takes breaking the rules. So for someone like Obama, Eric Holder was one of the best picks any president could have asked for.

But I don't actually think presidents "pick" their government as much as the real people in charge behind the curtain do.