The distinction between political- and performance-related reasons for removing a U.S. attorney is, in my view, largely artificial. A U.S. attorney who is unsuccessful from a political perspective, either because he or she has alienated the leadership of the department in Washington or cannot work constructively with law enforcement or other governmental constituencies in the district, is unsuccessful. - Kyle Sampson's Opening Statement to Senate Judiciary Committee, March 29, 2007.
http://www.washingtonpost.com/wp-dyn/content/article/2007/03/29/AR2007032900873.html