DURHAM, N.C. (AP) — Walter E. Dellinger, a constitutional scholar who argued numerous cases before the Supreme Court, served in top positions in the Justice Department and taught for decades at Duke University, 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.

While serving as acting solicitor general during the 1996-97 term of the high court, he personally argued nine cases, more than any of his predecessors in two decades at the time. Dellinger was an emeritus professor at the Duke University School of Law, where he had been a faculty member since 1969.

Ahead of the 2020 presidential election , Dellinger helped lead a legal team assembled by Democrats 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.

“There are approximately 25,000 Black female attorneys in America. There is every reason to believe that President Biden’s nomination process will benefit by focusing on that extraordinary group for the next justice of the United States Supreme Court,” Dellinger wrote.

An active commentator on legal, political and other news until just before his death, he also used his Twitter account to comment on Super Bowl commercials, sports and the rivalry between Duke and the University of North Carolina.

“Walter lived a wonderful and extraordinary life. He had many loves, first among them his wife Anne but also the State and University of North Carolina, the law and the rule of law, and American democracy,” said Hampton Dellinger, himself an assistant attorney general in the Biden administration’s Justice Department.

Walter Dellinger was born in Charlotte and attended the University of North Carolina and Yale Law School. Early in his career, Dellinger served as a law clerk to Supreme Court Justice Hugo Black.

“He devoted his professional life to the most gifted legal advocacy imaginable for causes and clients. He leaves so many friends behind and leaves this world a better place in so many ways,” his son said.

As acting solicitor general, he won five of the cases he argued himself, including when he defended the president's line-item veto and two cases defending state laws outlawing physician-assisted suicide. He got a split decision in another, and lost three, including when the high court threw out a key part of the Brady gun control law and allowed the Paula Jones sexual harassment lawsuit to proceed against Clinton.

“This is the best lawyer’s job in the world,” Dellinger said in a 1997 interview as he prepared to leave the role to return to Duke to teach. He told The Associated Press then that spending time with his family in North Carolina was a big part of his decision.

At the time, Clinton described Dellinger as someone who fought for all Americans' rights and praised his "his talent, his leadership, his energy and his sense of justice.”

Prior to that, while leading the Office of Legal Counsel, Dellinger issued opinions on the president’s authority to send U.S. troops to Haiti and Bosnia, as well as the president’s right to decline to enforce laws he believes are unconstitutional.

Overall, Dellinger argued 24 cases at the high court, representing the government and also private clients before and after his time in the administration, according to the legal information site oyez.org.

Dellinger was a mentor and friend to many Washington lawyers, especially among Democrats. White House chief of staff Ron Klain wrote on Twitter Wednesday, “Mourning the loss this morning of the great @walterdellinger -- wise counsellor, steadfast advocate, teacher and public servant -- a great mentor to me and so many others -- and a kind friend.”

Sherrilyn Ifill, president of the NAACP Legal Defense and Educational Fund, tweeted that Dellinger was a great attorney and “also a friend & consigliere to many, & a trusted ‘honest broker’ in our profession who could be called on as a respected & fair referee.”

North Carolina Gov. Roy Cooper called Dellinger a friend and “a force for good.” "Many people who never knew him were helped by the actions he took and the life he led," the Democrat said.

Former Judge Michael Luttig, a conservative, tweeted: “Walter Dellinger was a wonderful human being, a spectacular lawyer and counselor, and a friend. I am shocked and saddened to hear this news.”

Dellinger also will be missed by the Duke Law community, dean Kerry Abrams said.

“Walter Dellinger was a lion of the law, the legal profession, and legal education," she said in a statement. "A cherished member of the Duke Law School faculty for more than five decades, he was a true intellectual as well as being a generous and big-hearted colleague, mentor, and friend.”

___ Sherman reported from Washington.

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