The abuse of the Constitution that followed September 11, 2001, was neither surprising nor inevitable. It was not a surprise, because it wasn't the first time in American history—but the sixth, by my count—that fundamental rights had been violated during spasms of fear over national security. It was not inevitable, because prominent voices might have called the country back to its principles. There is no telling whether such appeals would have stood against the tide, but one man's words did make a difference in the emergency command center at FBI headquarters on Pennsylvania Avenue several hours after the attacks.