John Glover Roberts Jr.

John Glover Roberts Jr. (born January 27, 1955) is an American jurist who has served since 2005 as the 17th chief justice of the United States. Though primarily an institutionalist, he has been described as having a moderate conservative judicial philosophy. Regarded as a swing vote in some cases, Roberts has presided over an ideological shift toward conservative jurisprudence on the high court, in which he has authored key opinions.

Born in Buffalo, New York, Roberts was raised Catholic in Northwest Indiana and studied at Harvard University, initially intending to become a historian. He graduated in three years with highest distinction, then attended Harvard Law School, where he was the managing editor of the Harvard Law Review. Roberts served as a law clerk to Judge Henry Friendly and Justice William Rehnquist and held positions in the Department of Justice from 1989 to 1993 during the presidencies of Ronald Reagan and George H. W. Bush. He then became a partner at a law firm and built a leading appellate practice, arguing 39 cases before the Supreme Court.

In 1992, President George H. W. Bush nominated Roberts to the U.S. Court of Appeals for the District of Columbia Circuit, but the Senate did not hold a vote on his confirmation. In 2003, President George W. Bush appointed Roberts to the D.C. Circuit. In 2005, Bush nominated Roberts to the Supreme Court, initially as an associate justice to fill the vacancy left by Justice Sandra Day O'Connor but then as chief justice after Rehnquist's death. Roberts was confirmed by a Senate vote of 78–22. Aged 50, he was the youngest chief justice since John Marshall.

As chief justice, Roberts has authored majority opinions in many landmark cases, including National Federation of Independent Business v. Sebelius (upholding most sections of the Affordable Care Act), Shelby County v. Holder (limiting the Voting Rights Act of 1965), Trump v. Hawaii (expanding presidential powers over immigration), Carpenter v. United States (expanding digital privacy), Students for Fair Admissions v. Harvard (overruling race-based admission programs), and Trump v. United States (outlining the extent of presidential immunity from criminal prosecution). Roberts also presided over President Donald Trump's first impeachment trial.