Duff comes to the job with abundant experience in judicial administration. For four years, he was chief of staff and senior manager at the nation's highest court, coordinating the work of the court's 10 officers. He was Chief Justice Rehnquist's liaison with Congress, the executive branch and various state and federal organizations involved in the administration of justice. He assisted the Chief Justice in his roles as presiding officer of the presidential impeachment trial, chair of the Judicial Conference, chair of the Federal Judicial Center Board and Chancellor of the Smithsonian Institution. Over two decades of practice, Duff has litigated commercial cases involving matters ranging from antitrust to intellectual property to government contracts and has represented numerous clients in legislative matters in Congress.