The current Supreme Court, made up entirely of former federal appeals court judges, is in some ways the most insulated and homogenous in American history.

None of the justices have held elective office. All but one attended law school at Harvard or Yale. And the only three justices in American history who never worked in private practice are on the current court....

The current court is the first to be made up entirely of former federal appeals court judges. And only a few of those appeals courts at that: seven of the justices served on what might be called the court of appeals for the Acela circuit, in Boston, Philadelphia and Washington. (The exceptions are Justices John Paul Stevens, who served in Chicago, and Anthony M. Kennedy, who served in California.)