War powers

The war powers of the president are sweeping prerogative powers which presidents claim during times of national emergency.  They have their basis in the Constitution, statutory delegations of power to the President by Congress, and in judicial interpretation.

The constitutional foundation of presidential war power was laid by Lincoln during the Civil War when he married the commander-in-chief clause to the "take care that the laws be faithfully executed" clause. He used the resulting powers to justify a wide range of presidential actions such as:

1) activating state militias;
2) spending appropriated funds for unauthorized purposes;
3) suspending the writ of habeus corpus;
4) blockading Confederate ports

The Supreme Court upheld the legality of the blockade in the Prize Cases which declared that the president had a duty to defend the nation by appropriate means, including military action.

Also, the Court's refusal to overturn any of Lincoln's actions until after the end of the war set a precedent of judicial deference that would be followed in future wars (for example, the incarceration of Japanese- Americans during World War II, the War Labor Board with sweeping regulatory power, and FDR's demand (and congressional action) to repeal the Emergency Price Control Act (and creating of the Office of Price Administration).


Congress has also acquiesced in the expansion of presidential war powers by delegating to the president via a variety of statutes.