Reports indicate that President Donald Trump intends to nominate Charles Cooper, a well-liked and well-respected Washington lawyer who served in the Reagan administration, to serve as the U.S. solicitor general. Cooper is perhaps best known for his defense of California’s Proposition 8, which barred same-sex marriage in that state. By a vote of 5-4, the justices ruled that the proponents of the law did not have a legal right to defend the ban in court after state officials had declined to do so.

If nominated and confirmed, Cooper would bring a strong conservative pedigree to the job. He graduated first in his class from the University of Alabama Law School and then went on to serve as law clerk to then-Justice William H. Rehnquist. In 1981, he joined the Reagan administration by taking a job in the Civil Rights Division of the U.S. Department of Justice; four years later, he became the head of the Justice Department’s Office of Legal Counsel. Since 1988, Cooper has worked as a lawyer in private practice, spending the last two decades as a partner in a law firm that he co-founded, and has argued before the Supreme Court seven times. But although Cooper has often represented conservative interests, he is generally not regarded as a conservative ideologue.

Cooper is a close friend of Sen. Jeff Sessions, the Alabama lawmaker whom Trump has nominated to serve as attorney general, and helped to prepare Sessions for his confirmation hearings. Like Sessions, Cooper could prove to be a controversial pick. In addition to his role defending California’s ban on same-sex marriage, Cooper also signed a brief on behalf of the federal government supporting Bob Jones University in its challenge to the constitutionality of an Internal Revenue Service policy denying tax exemptions to religious institutions that discriminate based on race. The university had argued that its ban on interracial dating was based on its sincere religious beliefs, but the Supreme Court upheld the IRS policy, by a vote of 8-1. And in 1986, as the head of the Office of Legal Counsel, Cooper signed an OLC opinion that argued that employers could reject job applicants with AIDS if they were concerned about contracting the disease.

The solicitor general is often nicknamed the “tenth justice,” because of the critical role that he or she plays representing the federal government before the Supreme Court. With the real possibility that challenges to the president’s recent initiatives, especially his January 27 executive order on immigration, could reach the Supreme Court soon, Cooper’s nomination could take on increased urgency. This is particularly true for the January 27 travel ban: Although Noel Francisco, the Trump administration’s principal deputy solicitor general, appeared as the acting solicitor general on the government’s application to the U.S. Court of Appeals for the 9th Circuit for a stay of the federal district court’s order blocking the travel ban, he did not appear on the government’s reply brief because his former law firm filed a “friend of the court” brief in the case supporting the states.

One of the other finalists for the job was reportedly George Conway, a New York attorney who is the husband of Kellyanne Conway, the counselor to the president. George Conway is also a well-regarded lawyer who has argued before the Supreme Court – albeit only once – but nominating him may have raised questions about the solicitor general’s traditional independence from the White House. By contrast, Cooper would lack a direct connection to the White House and would have the added advantage of being better known to the justices.