John Glover Roberts Jr. (born January 27, 1955) is an American lawyer and jurist who serves as Chief Justice of the United States. Roberts has authored the majority opinion in several landmark cases, including Shelby County v. Holder, National Federation of Independent Business v. Sebelius, King v. Burwell, and Department of Commerce v. New York. He has been described as having a conservative judicial philosophy but has shown a willingness to work with the Supreme Court's liberal bloc, and since the retirement of Anthony Kennedy in 2018 has come to be regarded as a key swing vote on the Court. Roberts presided over the impeachment trial of President Donald Trump. Roberts grew up in northwestern Indiana and was educated in Catholic schools. He studied history at Harvard College and then attended Harvard Law School, where he was managing editor of the Harvard Law Review. He served as a law clerk for Circuit Judge Henry Friendly and then-associate justice William Rehnquist before taking a position in the attorney general's office during the Reagan Administration. He went on to serve the Reagan administration and the George H. W. Bush administration in the Department of Justice and the Office of the White House Counsel, before spending 14 years in private law practice. During this time, he argued 39 cases before the Supreme Court. Notably, he represented 19 states in United States v. Microsoft Corp. In 2003, Roberts was appointed as a judge of the U.S. Court of Appeals for the D.C. Circuit by George W. Bush. During his two-year tenure on the D.C. Circuit, Roberts authored 49 opinions, eliciting two dissents from other judges, and authoring three dissents of his own. In 2005, Roberts was nominated to be an associate justice of the Supreme Court, initially to succeed the retiring Sandra Day O'Connor. When Rehnquist died before Roberts's confirmation hearings began, Bush instead nominated Roberts for Chief Justice and later appointed Samuel Alito as Associate Justice.