chief administrative body of the United States federal courts. The Judicial Conference is empowered by the Rules Enabling Act to propose rules, which are then promulgated by the Supreme Court (subject to disapproval by Congress under the Congressional Review Act), to ensure the smooth operation of the federal courts. Major portions of the Federal Rules of Civil Procedure and Federal Rules of Evidence have been adopted by most state legislatures and are considered canonical by American law schools. Appoints sitting federal judges to the membership of the United States Foreign Intelligence Surveillance Court, a "secret court" which oversees requests for surveillance warrants by federal police agencies (primarily the FBI) against suspected foreign intelligence agents inside the United States. (see ). Appoints sitting federal judges to the membership of the United States Alien Terrorist Removal Court, a special court constituted to determine whether aliens should be deported from the United States on the grounds that they are terrorists. Appoints the members of the Judicial Panel on Multidistrict Litigation, a special tribunal of seven sitting federal judges responsible for selecting the venue for coordinated pretrial proceedings in situations where multiple related federal actions have been filed in different judicial districts. Serves as an ex officio member of the Board of Regents and as the chancellor of the Smithsonian Institution. Supervises the acquisition of books for the Law Library of the Library of Congress. Unlike Senators and Representatives, who are constitutionally prohibited from holding any other "office of trust or profit" of the United States or of any state while holding their congressional seats, the chief justice and the other members of the federal judiciary are not barred from serving in other positions. John Jay served as a diplomat to negotiate the Jay Treaty, Robert H. Jackson was appointed by President Truman to be the U.S. prosecutor in the Nuremberg trials of leading Nazis, and Earl Warren chaired the President's Commission on the Assassination of President Kennedy. Disability or vacancy Under , when the chief justice is unable to discharge their functions, or when that office is vacant, the chief justice's duties are carried out by the most senior associate justice until the disability or vacancy ends. Currently, Clarence Thomas is the most senior associate justice. List of chief justices Since the Supreme Court was established in 1789, the following 17 men have served as Chief Justice: Notes References Further reading Flanders, Henry.