Scholars differ also in their views of Franklin D. Roosevelt's use of the war power. Critics accused him of lying to the public in trying to involve the nation in Second World War. In September 1940 when he gave fifty over-age destroyers to Britain in exchange for bases, they called it an act of war and him a dictator. These dissenters comprised a minority. Much of the public applauded his initiative.

When Japan attacked, Roosevelt properly asked congress to recognize that a state of war existed. Congress did so but opponents charged he had brought the nation into war through deception. The public disagreed, rallying around the president, the flag, and the war effort. With augmented power voted by congress, he waged war with virtually dictatorial authority. Through it all, most of the public praised him while his intellectual defenders formed a kind of cult that exalted the strong presidency and belittled the constitutional authority of congress.
Legal scholars pointed out correctly that previous executive breaches of the constitution did not validate subsequent violations.

During Harry S. Truman's presidency and the cold war years, this cult flowered. Historians wrote multi-volume biographies of presidents, most of which praised their subjects. Intellectuals and others lobbied for presidential libraries built under the guise of aiding scholarship but usually to glorify presidents. As for Truman, even though he came to office admitting insufficient knowledge to lead a mighty nation at war, he quickly learned that anti-communism and macho behavior played well with the public.