The instinctive dialectic of politics thus offers a measure of insurance against the possibility that emergency prerogative might lead to post-emergency despotism. Yet the danger persists that power asserted during authentic emergencies may create precedents for transcendent executive power during emergencies that only exist in the hallucinations of the oval office and that remain invisible to most of the nation. The perennial question is: how to distinguish real crises threatening the life of the republic from bad dreams conjured up by paranoid Presidents spurred on by paranoid advisors? Necessity, as Milton said, is the always “the tyrant’s plea.”

Arthur Schlesinger, Jr., “War and the Constitution: Abraham Lincoln and Franklin D. Roosevelt,” The Gettysburg Review 2 (Winter 1989) 23. Delivered in slight different form as the Fortenbaugh Lecture on November 19, 1988.