Justice Anthony Kennedy announced his retirement, effective July 31. Justice Kennedy’s greatest judicial legacy was his championship of gay rights. He wrote every major gay rights decision, including one called Obergefell, which established a constitutional right to same-sex marriage, and it will be what he is most remembered for. Justice Kennedy was a moderate conservative; voted more often with the court’s conservative wing; was the author of Citizens United, which amplified the role of money in politics; cast a vote with the five-justice majority in Bush v. Gore in 2000, which handed the presidency to President George W. Bush — “I George Walker Bush, do solemnly swear.” — joined the five-justice majority in District of Columbia against Heller, which revolutionized Second Amendment law and established a personal right to keep and bear arms. He was often prepared to cut back on the death penalty, whether it involved people with intellectual disabilities, people who committed crimes when they were younger than 18 or people who committed crimes other than murder. He joined the controlling opinion and in a 1992 decision, Planned Parenthood against Casey, which re-established and saved Roe v. Wade, the decision that guarantees a constitutional right to abortion. And in recent years, he has joined the court’s liberals in cases on affirmative action and abortion. And those cases in which Justice Kennedy joined the court’s four more liberal members are almost certainly at risk if President Trump appoints a conservative to the court.