Continued assertions of a presidential prerogative power, broad enough, in the literary tradition of the Lockean Prerogative to permit the president in an emergency to act in the absence or violation of law, raises anew the question of the existence, source, and scope of such extraordinary authority. This article explains that the framers of the Constitution delivered a constitutional and historical rebuke to the concept of executive prerogative. As Justice Jackson observed in the Steel Seizure Case, the framers recognized that the possession of an emergency power would “tend to kindle emergencies.” Presidential violation of the Constitution is illegal, and can be made legal only through congressional passage of retroactive ratification.