Donald Ayer was drawn to public service primarily as a result of living through the experience of Watergate while he was in law school. After clerkships with Judge Malcolm Wilkey of the D.C. Circuit and then-Justice William H. Rehnquist, he served for over ten years in the U.S. Department of Justice, including positions as an Assistant U.S. Attorney during the late 1970s, as United States Attorney for the Eastern District of California and as Principal Deputy Solicitor General under President Reagan, and as Deputy Attorney General under President George H.W. Bush. He was greatly influenced by the extensive reforms and key principles enunciated by Attorney Generals Edward Levi and Griffin during the late 1970s to address the failings highlighted by Watergate. When the challenges to evenhanded justice began in earnest in the Trump administration, he became a strong advocate, in print and other media, for the rule of law and for the key principles essential to its preservation. Following his departure from the Department of Justice in 1990, Don joined the Washington office of Jones Day, where his work focused primarily on appellate litigation, including a substantial amount of pro bono work. He has argued a total of 19 cases in the U.S. Supreme Court, and served as President of the American Academy of Appellate Lawyers and as President of the Edward Coke Appellate Inn of Court. Since 2006, he has taught a course in Supreme Court Advocacy at Georgetown Law School, and has also taught at Duke, NYU, and Stanford Law Schools.