Federal laws that regulate state institutions give rise to what the Supreme Court has described as the oldest question of constitutional law. In recent years, the Court has confronted questions of congressional power to regulate state legislatures and executives, but has not directly confronted any question of congressional power to regulate state courts. Since the Founding, questions of congressional power to regulate state court jurisdiction of Article III cases have arisen - most notably, congressional power to assign jurisdiction of federal criminal cases to state courts. Today, significant questions of congressional power to regulate state court jurisdiction over non-Article III cases are arising for the first time in American history....