For a long time, for both Justices and many observers, "legitimacy" was a focal point for assessing the Supreme Court's performance. Legitimacy may have mattered implicitly earlier, but this criterion surged into the open following the extraordinary discussion of the topic in Planned Parenthood of Southeastern Pennsylvania v. Casey.1 "The Court's power lies in its legitimacy," Justices Kennedy, O'Connor, and Souter explained in their joint opinion reaffirming abortion rights, "a product of substance and perception that shows itself in the people's acceptance of the Judiciary as fit to determine what the Nation's law means and to declare what it demands."2 The reference was to what has been called descriptive or sociological legitimacy: the fact of popular acceptance of the institution's role.3
