When President Ronald Reagan appointed Sandra Day O'Connor to the Supreme Court, in 1981, O'Connor was a judge on a state appellate court in Arizona. Since then, all new justices have been judges on federal circuit courts of appeals.
In October of 1971, President Richard Nixon was presented with the unusual situation of appointing two new justices simultaneously. John Marshall Harlan II had retired the previous month, three months before his death from cancer. Also in September 1971, Hugo Black retired, just days before his death, following a stroke.
Nixon's two nominees were William Rehnquist and Lewis Powell. Rehnquist had been in private practice in Phoenix, and was an assistant attorney general in Nixon's administration. Powell's entire legal career had been in private practice. Those two justices are the most recent ones who had no experience as a judge, prior to joining the Supreme Court.
That's a bit misleading, however. Clarence Thomas had been an appeals court judge for less than two years, when President George H.W. Bush appointed him to the Supreme Court. Thomas's previous experience had been in state government, and in the legislative and executive branches of the federal government.
David Souter had been a federal appellate judge for less than five months when he became an associate justice, also having been appointed by the elder Bush. Souter, however, had been a judge in the New Hampshire state judiciary for 12 years.
Now, President Obama has nominated Elena Kagan to the Supreme Court. She has never been a judge. There has already been much talk about whether someone from that background is qualified to join the Supremes, and there will be much more of that, during the next few weeks.
Those on one side of the argument say that long-time judges bring a uniformly sterile view of constitutional concepts, with insufficient appreciation of the impact of those concepts on everyday life.
The counterargument is that, when politicians join the Court, they are the ones who are most likely to legislate from the bench, judging according to their policy preferences, rather than the dictates of applicable law.
That's an interesting question. As with all issues connected to modern Supreme Court nominations, it will probably generate more heat than light. But I hope for at least some enlightened debate on the topic.