As chief of staff, Addington supervised the Vice President's staff. In both roles, Addington also provided advice to the White House staff, as he had the additional role of Assistant to the President, as his predecessor Scooter Libby had likewise held. As vice presidential counsel, Addington is known for his focus on the constitutional independence of the Vice President. He tried to protect the inner workings of the Office of the Vice President from investigations by the Government Accountability Office (GAO) and private organizations.