In its decision to uphold the travel ban, the Supreme Court also repudiated a long-discredited ruling that nonetheless stood until Tuesday — the case that upheld the constitutionality of forcing Americans of Japanese descent into detention camps during World War II. The opportunity to revisit the ruling presented itself in a dissenting opinion by Justice Sonia Sotomayor, which compared the internment of Japanese-Americans to groups affected by the Trump travel ban.

Chief Justice John Roberts rejected the comparison, but said the reference to Korematsu v. the United States "affords this Court the opportunity to make express what is already obvious: Korematsu was gravely wrong the day it was decided, has been overruled in the court of history, and—to be clear—'has no place in law under the Constitution.'"

Roberts wrote in the majority opinion, "Whatever rhetorical advantage the dissent may see in doing so, Korematsu has nothing to do with this case. The forcible relocation of U. S. citizens to concentration camps, solely and explicitly on the basis of race, is objectively unlawful and outside the scope of Presidential authority. But it is wholly inapt to liken that morally repugnant order to a facially neutral policy denying certain foreign nationals the privilege of admission."

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Sotomayor praised the court for its rejection of Korematsu, saying, "This formal repudiation of a shameful precedent is laudable and long overdue," but she disagreed that comparing the two was inappropriate.

"As here, the Government invoked an ill-defined national-security threat to justify an exclusionary policy of sweeping proportion," Sotomayor wrote. "As here, the Government was unwilling to reveal its own intelligence agencies' views of the alleged security concerns to the very citizens it purported to protect."

"And as here," Sotomayor continued, "there was strong evidence that impermissible hostility and animus motivated the Government's policy."

Judge Robert Jackson, in his famous dissent in Korematsu (which was the late Justice Antonin Scalia's favorite opinion), argued that the court's affirmation of the internment order was a "far more subtle blow to liberty than the promulgation of the order itself," given that the military order would not last beyond the duration of the military emergency. But once the court weighed in with a constitutional rationale, "the Court for all time has validated the principle of racial discrimination in criminal procedure and of transplanting American citizens. The principle then lies about like a loaded weapon, ready for the hand of any authority that can bring forward a plausible claim of an urgent need."

Few would defend Franklin Roosevelt's wartime executive order today, but it was a hypothetical question that President Trump was asked when he was still a candidate, after he first proposed his travel ban. He told Time in a 2015 interview that he wasn't sure whether or not he would have supported the internment of Japanese-Americans. "I would have had to be there at the time to tell you, to give you a proper answer," he told Time. "I certainly hate the concept of it. But I would have had to be there at the time to give you a proper answer."

All this said, though, CBSN contributor and Cato Supreme Court Review editor-in-chief Ilya Shapiro notes that an academic debate has broken out on Twitter over whether today's opinion constituted "a formal overturning of Korematsu, dicta, or just saying bad things about Korematsu." It is, he said, quite literally an academic debate, "because I don't know of any court or lawyer who's cited Korematsu favorably in the last 50+ years."

"All in all," says Shapiro, "I think it's fair to say that no court in this country will approve putting U.S. citizens into camps any time soon."