Newswise — According to Michal Belknap the "requirement" that Supreme Court appointees be federal appeals court judges is actually a recent development. Belknap is a legal historian and constitutional law professor at California Western School of Law in San Diego. "Until about 20 years ago," he says, "it was more common that justices had not been judges." He cites Chief Justices William Rehnquist and Earl Warren as two high-profile examples.

"The trend of almost exclusively nominating federal appellate court judges is a bad development," he says, "and it has become the standard over the last generation specifically in response to the political controversies over Roe v. Wade." According to Belknap, presidents were often looking for potential nominees with a paper trail divulging their opinions on abortion.

Belknap's research specializes in the history of civil rights and civil liberties in 20th century America. He has written extensively about the U.S. Supreme Court, including recent books, The Supreme Court Under Earl Warren (2005), and The Vinson Court: Justices, Rulings and Legacy (2004), both of which examine how the respective Court's rulings shaped U.S. legal history.

"The problem with Harriet Miers is not that she has no judicial experience," says the California Western School of Law professor, "it's that she is a close advisor to the president, a situation that hasn't worked out very well in the past." For example, he notes, Chief Justice Earl Warren, who is generally rated as one of the top Chief Justices in history, was a former attorney general and governor of California. "In fact the Warren Court, which overturned Brown v. Board of Education and significantly expanded civil rights, was dominated by justices who were never judges."

If a nominee hasn't been an appellate court judge, they might not know everything about constitutional law, he points out, "but they might be familiar with other areas of law often addressed by the Court." He explains: "The Supreme Court spends much of its time interpreting federal statutes, and having justices with varied backgrounds--tax law, trial attorneys, criminal law--can actually be an asset."