What did the supreme court decide in korematsu v. united states (1944) regarding the internment of american citizens of japanese ancestry living on the west coast of the united states?

Early in World War II, on February 19, 1942, President Franklin Roosevelt issued Executive Order 9066, granting the U.S. military the power to ban tens of thousands of American citizens of Japanese ancestry from areas deemed critical to domestic security. Promptly exercising the power so bestowed, the military then issued an order banning "all persons of Japanese ancestry, both alien and non-alien" from a designated coastal area stretching from Washington State to southern Arizona, and hastily set up internment camps to hold the Japanese Americans for the duration of the war. In defiance of the order, Fred Korematsu, an American-born citizen of Japanese descent, refused to leave his home in San Leandro, California. Duly convicted, he appealed, and in 1944 his case reached the Supreme Court.

A 6-3 majority on the Court upheld Korematsu's conviction. Writing for the majority, Justice Hugo Black held that although "all legal restrictions which curtail the civil rights of a single racial group are immediately suspect" and subject to tests of "the most rigid scrutiny," not all such restrictions are inherently unconstitutional. "Pressing public necessity," he wrote, "may sometimes justify the existence of such restrictions; racial antagonism never can." 

In Korematsu's case, the Court accepted the U.S. military's argument that the loyalties of some Japanese Americans resided not with the United States but with their ancestral country, and that because separating "the disloyal from the loyal" was a logistical impossibility, the internment order had to apply to all Japanese Americans within the restricted area. Balancing the country's stake in the war and national security against the "suspect" curtailment of the rights of a particular racial group, the Court decided that the nation's security concerns outweighed the Constitution's promise of equal rights.

Justice Robert Jackson issued a vociferous, yet nuanced, dissent. "Korematsu ... has been convicted of an act not commonly thought a crime," he wrote. "It consists merely of being present in the state whereof he is a citizen, near the place where he was born, and where all his life he has lived." The nation's wartime security concerns, he contended, were not adequate to strip Korematsu and the other internees of their constitutionally protected civil rights. 

In the second half of his dissent, however, Jackson admitted that ultimately, in times of war, the military would likely maintain the power to arrest citizens -- and that, possessing no executive power, there was little the judicial branch could do to stop it. Nonetheless, he resisted the Court's compliance in lending the weight of its institutional authority to justify the military's actions, and contended that the majority decision struck a "far more subtle blow to liberty" than did the order itself: "A military order, however unconstitutional, is not apt to last longer than the military emergency. ... But once a judicial opinion rationalizes such an order to show that it conforms to the Constitution, or rather rationalizes the Constitution to show that the Constitution sanctions such an order, the Court for all of time has validated the principle of racial discrimination. ... The principle then lies about like a loaded weapon ready for the hand of any authority that can bring forward a plausible claim of urgent need."

Justice Owen Roberts also dissented in the case, arguing that a relocation center "was a euphemism for prison," and that faced with this consequence Korematsu "did nothing." Also dissenting, Justice Frank Murphy harshly criticized both the majority and the military order, writing that the internment of the Japanese was based upon "the disinformation, half-truths and insinuations that for years have been directed against Japanese Americans by people with racial and economic prejudices."