Why Chief Justice Roberts is moving to the center of the court

As chief justice, John Roberts must both protect the U.S. Supreme Court’s integrity in a polarized era and be true to his conservative values. How might he balance both goals?

There is a convention that U.S. Supreme Court history is described not in “eras” or “ages,” or even decades, but by chief justices. Think “the Marshall Court” and “the Brennan Court.”

Chief Justice John Roberts has never understood that convention. The chief doesn’t have that much more power than the other justices, he has said. Nevertheless, “the Roberts Court” has...