SAN FRANCISCO — If Paul Watford were promoted to the U.S. Supreme Court, he’d become the second African-American justice on the current court and its only member without an Ivy League diploma.

Should President Barack Obama look for diversity in a nominee who also has won high marks for his moderation, Watford would fill the bill as a potential replacement for the late Justice Antonin Scalia.

The California-educated Watford has been a judge on the 9th U.S. Circuit Court of Appeals for nearly four years. Earlier, he was a federal prosecutor and held clerkships with a Republican-appointed judge and a Supreme Court justice chosen by a Democrat.

“If a candidate were to be evaluated on the merits as opposed to some meta-political issue, I would think there’s a lot about Paul’s intellect and judicial demeanor and his temperament generally that should be appealing to both sides,” said Sean Gallagher, a partner at a Chicago law firm who clerked with Watford for 9th Circuit Judge Alex Kozinski in 1994-95.

Watford has spent nearly four years on the 9th Circuit, where in his opinions and dissents, he appears less interested in making law than resolving disputes, said Arthur Hellman, a law professor at the University of Pittsburgh and a scholar of the 9th Circuit.

“He’s not playing to any audience,” Hellman said. “He’s not doing it for glory. He’s doing it because he thinks his job requires it.”

Watford was among 10 judges who overruled a smaller 9th Circuit panel last year and said YouTube should not have been forced to take down an anti-Muslim film that sparked violence in the Middle East and death threats to actors. The 10-1 ruling found that the actress who wanted the film removed had no copyright claim to it.

Watford sided with the majority, but said it was wrong to expand the scope of the case to include “new rules of copyright law” and could have decided the issue on much narrower grounds.

“He is someone who is very careful, who decides things very narrowly and somebody who does not use opinions as pedestals for making public policy,” Kozinski said.

The U.S. Senate confirmed Watford to the 9th Circuit in a 61-34 vote that included Republican support. If nominated and confirmed to the Supreme Court, he would join Justice Clarence Thomas as the second African-American among the current justices.