Despite the opprobrium heaped on the Supreme Court’s modern doctrine of state sovereign immunity, there is a theory that makes sense of that doctrine, and also renders it consistent with the constitutional text. The theory is that sovereign immunity is a common law rule—a “backdrop”—that is not directly incorporated into the Constitution, but is shielded by the Constitution from most kinds of change.
That theory also has important implications for the future of sovereign immunity. The Supreme Court’s decision in Nevada v. Hall holds that state sovereign immunity need not be respected in another state’s courts. Last term, in Franchise Tax Board v. Hyatt, the Court nearly overruled Hall, and its future hangs by a single vote. The backdrop theory suggests that Hall is rightly decided, consistent with modern doctrine, and should not be overruled.