Walter E. Dellinger, a noted constitutional scholar who argued numerous cases before the Supreme Court, served in top positions in the Justice Department and was a professor at Duke Law School, died Wednesday. He was 80.

Dellinger died Wednesday morning in Chapel Hill, North Carolina, his son Hampton Dellinger said.

During the administration of former President Bill Clinton, Dellinger headed up the influential Office of Legal Counsel that advises the attorney general on often sensitive legal and policy issues and served as the acting Solicitor General, the administration’s top Supreme Court lawyer.

During his time as acting solicitor general during the 1996-97 term of the high court, he argued nine cases including those dealing with doctor-assisted suicide and the line-item veto, according to his Duke Law biography. Dellinger was an emeritus professor at Duke, where he had been a faculty member since 1969.

Dellinger was a leader of a legal team assembled by Democrats ahead of the 2020 presidential election to take on election-related court cases. And in early February, Dellinger spoke out in defense of Biden’s pledge to name a Black woman to the Supreme Court in an essay published by the New York Times.