Hirabayashi v. United States

Before the Supreme Court, Hirabayashi denied neither that he disobeyed the curfew, nor that it was authorized by the President's Executive Order and was punishable under the act of Congress. He even agreed that the exclusion order was a prudent defense measure, if applied to all citizens. What he challenged was that Congress had unconstitutionally delegated powers to the military, and even if those powers had been lawfully delegated, the curfew and exclusion orders discriminated against citizens of Japanese descent.

In its decision, the Court focused on the importance of the conditions under which the disputed regulations were imposed. Writing for the unanimous Court, Chief Justice Stone began with the principle that "the war power of the national government is the power to wage war successfully," which he said included protection of war materials and personnel against harm. Consequently, he reasoned, when conditions required, as the Court believed they did in the weeks and months following the Pearl Harbor attack, it was appropriate for the president and Congress to defer to the judgment and discretion of the military in defending against espionage and sabotage. This deference was obvious throughout the decision--"it is not for any court to sit in review of the wisdom of [military] action or substitute its judgment for theirs."

Justice Stone went on to outline the justifications that the military commander had given for imposing the challenged regulations on Japanese Americans. He made it clear that the Court accepted the military's findings that there was not enough time for individual hearings to determine who were the loyal and disloyal among the Japanese Americans living in restricted areas. It is interesting to note that the Court accepted prevailing cultural factors as support for military belief in the necessity of restricting and relocating Japanese Americans. It said, "social, economic, and political conditions which have prevailed since the close of the last century, when the Japanese began to come to this country . . . , have intensified their solidarity and prevented their assimilation [into] the white population."

The Court was careful to note that racial classifications were under most circumstances irrelevant and unlawful. In one of the most echoed remarks of the decision, the Court said that "distinctions between citizens solely because of their ancestry are by their very nature odious to a free people whose institutions are founded upon the doctrine of equality." The Court further reasoned though, that it did not necessarily follow that during wartime, government could not take ancestry into account when doing what it deemed necessary to successfully wage war and defend national interests. Largely because it deferred to military intelligence, and despite as has been argued, to racist suspicion, the Court found nothing unconstitutional in the curfew and upheld Hirabayashi's conviction. He was imprisoned at an Arizona federal road camp. From the question of internment, the Court distanced itself, saying, "we need not now attempt to define the ultimate boundaries of the war power."