Supreme Court Associate Justice Anthony Kennedy, a conservative who provided key votes for same sex-marriage, abortion access and affirmative action, has announced he will retire.

He notified President Trump in a letter today, telling him that effective July 31, he would “end my regular active status as an Associate Justice of the Supreme Court, while continuing to serve in a senior status.”

Kennedy was nominated in 1987 by President Reagan to the court, after Robert Bork’s nomination failed and Douglas Ginsburg was pressured to withdraw after questions were raised about his admission he had smoked marijuana several times.

Kennedy’s retirement gives Trump his second nomination, following Justice Neil Gorsuch, and will likely transform the Supreme Court for generations.