On Dec. 8, 2017, a lawyer for the U.S. government stood before a federal appeals court to defend President Donald Trump’s third attempt to ban immigrants and visitors from predominantly Muslim countries. He argued that while there may be legal limits on presidential power to ban noncitizens from the United States, the courts should still defer to the executive branch, taking Donald Trump’s word for it that he is no longer intent on banning Muslims from the United States.

The judges might have asked, “What is the historical precedent that supports President Trump’s position on the travel ban?” None of them asked that precise question, but the President himself gave a chilling answer when he proposed the ban: Korematsu v. United States, the 1944 Supreme Court decision upholding Executive Order 9066, which banished Japanese Americans from their homes and forced them into prison camps. The Korematsu ruling came down 73 years ago today and the lessons from it could not be more relevant.

While Korematsu is technically still on the Supreme Court’s books, the decision is nearly universally repudiated today. In 1988, Congress passed the Civil Liberties Act, which issued a formal apology and offered reparations to each survivor. And the Acting Solicitor General of the United States made a formal confession of error in 2011, noting it as a deeply regretted episode of American history, an instance of wartime hysteria leading to a gross injustice.

President Trump didn’t stop at invoking the racism and outright chicanery of the U.S. government that underlay the Korematsu decision. He also declared that “Islam hates us” and that “we’re having problems with the Muslims, and we’re having problems with Muslims coming into the country.” In March 2017, after taking office and attempting to carry out the first two versions of his Muslim ban, Donald Trump asserted that “[t]he assimilation [of Muslims in the U.S.] has been very, very hard. It’s been a very, very difficult process”— smearing more than 3 million people in one fell swoop.

Today, the president echoes General John DeWitt, the commander of the U.S. Army’s Western Defense Command during World War II, who infamously supported the wholesale “exclusion” of Japanese Americans, saying: “A Jap's a Jap. It makes no difference whether the Jap is a citizen or not.”

The echoes of Korematsu don’t end with the reliance on racist stereotypes. Donald Trump has repeatedly asserted that his Muslim ban serves national security interests. His latest version, issued on Sept. 24, is couched vaguely in terms of the national interest. But reports by the Department of Homeland Security leaked in February showed that citizenship is an “unlikely predictor” of terrorism threats to the United States and that very few people from Iran, Iraq, Libya, Somalia, Sudan, Syria, and Yemen, the countries listed in the first Muslim ban, have committed terrorism. A bipartisan group of former national security officials has filed declarations and briefs with the federal courts stating that there is no legitimate national security purpose served by the ban. And the Cato Institute has filed an amicus brief setting out its research showing that the president’s national security assertions are simply wrong.

During World War II, the American government also invoked national security to justify what should have been unjustifiable—the detention of U.S. citizens solely because of their national origin and ethnicity—and insisted that the courts must defer to an agency study to do so. In Korematsu, the government submitted a report by General DeWitt asserting that Japanese Americans posed an unacceptable risk of sabotage on the west coast. Decades later, researchers proved that government lawyers had suppressed critical evidence: The Office of Naval Intelligence, the FBI, and the Federal Communications Commission had all debunked the allegations made in the DeWitt report before it was submitted to the Supreme Court and intelligence and law enforcement investigations had concluded that only a handful of individuals posed a threat and had already been arrested.

The Korematsu decision remains deeply disturbing, particularly because the government still takes the same position in the Muslim ban litigation. In support of a ban affecting Muslims categorically, President Trump declared, “You don’t know who is who.” In 1944, the Supreme Court used the same justification: “It was because we could not reject the finding of the military authorities that it was impossible to bring about an immediate segregation of the disloyal from the loyal that we sustained the validity of the curfew [and detention] order as applying to the whole group.” Today, the president asks the courts to double down on Korematsu’s discredited conclusion.

Chillingly, in Korematsu the Supreme Court explicitly overrode fundamental constitutional norms on the fraudulent word of the executive branch. The court noted that the incarceration of a group based on their race “is inconsistent with our basic governmental institutions. But when under conditions of modern warfare our shores are threatened by hostile forces, the power to protect must be commensurate with the threatened danger.”

In his dissent, Justice Jackson noted, “[O]nce a judicial opinion rationalizes such an order [as Executive Order 9066] 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 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 an urgent need.”

Since Korematsu, generations of civil rights lawyers have been inspired to take action to prevent a recurrence. In the 1980s, historian Peter Irons and researcher Aiko Yoshinaga-Herzig uncovered the government’s deceptions and young Asian American lawyers, including Dale Minami, Don Tamaki, Bob Rusky, Karen Kai, Lori Bannai, Dennis Hayashi, Donna Komure, Leigh Ann Miyasato, Eric Yamamoto, Ed Chen, Akira Togasaki and Debbie Ching, set out to right the wrong the U.S. government committed against Fred Korematsu, Min Yasui, and Gordon Hirabayashi, three Japanese Americans who courageously challenged the government’s “exclusion” and curfew laws during World War II.

Through the exercise of legal ingenuity and hard work, the lawyers succeeded in exposing the government’s 40-year-old lies and won a U.S. district court order vacating the wartime convictions. Today, the children of Fred Korematsu, Gordon Hirabayashi, and Min Yasui have filed friend-of-the-court briefs to support Muslims in the United States and others who have challenged President Trump’s ban. Their message is simple and profound: “Blind deference to the Executive Branch, even in areas in which decision makers must wield wide discretion, is incompatible with the protection of fundamental freedoms. Meaningful judicial review is an essential element of a healthy democracy.”

In short, we won’t go back.

This piece was originally published at NBC's THINK.

Facebook has admitted a serious problem with the platform’s advertising function that is allowing racial discrimination on its site. But there is a way to fix it — if the company is willing.

In the spring of 2016, Facebook rolled out its “ethnic affinity” feature, which allowed advertisers to target Facebook users labeled as African American, Latino, or Asian American based upon their behavior on Facebook. Advertisers could opt to include or to exclude users in these categories. Facebook said that these labels were not equivalent to race because they were based not on users’ actual racial identities, but on whether they engaged with Facebook pages associated with those racial communities. Nonetheless, it identified the categories as “demographics” in its options for advertisers.

The system made it easy to exclude users marked as African American from seeing ads for anything, including job postings and credit or housing opportunities. Yet civil rights laws like the Fair Housing Act make this kind of discriminatory advertising illegal.

In October 2016, ProPublica was able to place a housing-related ad that targeted house hunters and those likely to move, excluding users marked as African American, Asian American, or Hispanic. The story prompted an immediate outcry. The Congressional Black Caucus contacted Facebook, and the Department of Housing and Urban Development, which enforces fair housing laws, said the revelations raised “serious concerns.”

Make no mistake, this is not simply an advertising problem — this is a civil rights problem made all the more dangerous by social media’s technological advances. Online personalization opens up significant possibilities for discrimination against marginalized communities, including people of color and other members of protected classes. In the offline world, we have thankfully moved past the era of housing advertisements that explicitly stated that people of certain races, religions, or ethnicities could not apply. But with behavioral targeting online, discrimination no longer requires that kind of explicit statement. Instead, a property manager can simply display ads for housing only to white people, or Christians, or those without disabilities.

In response to ProPublica’s 2016 investigation, Facebook expressed a desire to solve this discrimination problem built into its ad targeting business. We at the ACLU and other advocates spent many hours helping the company move toward some fixes. We helped Facebook settle on a system that we were told would use machine learning to detect ads for housing, credit, or employment and treat them differently. In those categories, Facebook promised, ethnic targeting would be impossible and advertisers would have to certify that they were not violating the law or Facebook’s anti-discrimination policy before their ads would run.

Discrimination in the rental market is one of the most toxic forms of contemporary discrimination. 

At the time, we praised Facebook’s changes — although they left some significant questions unanswered — hoping acknowledgment of the civil rights laws would become standard throughout the online advertising ecosystem.

Fast forward to last week. ProPublica tested the system again and found that Facebook was still allowing advertisers to prevent users from seeing an ad for rental housing based on race, now rechristened “multicultural affinity.” ProPublica was also able to exclude people in wheelchairs and Spanish speakers, among others.

We have been extremely disappointed to see these significant failures in Facebook’s system for identifying and preventing illegal advertising discrimination. Facebook’s representations to us over the course of the last year indicated that this problem had been substantially solved, but it now seems clear that was not the case. Discrimination in the rental housing market is one of the most toxic and tenacious forms of contemporary discrimination. And, as the recent Pulitzer Prize-winning book “Evicted” demonstrates, discrimination in rental housing is a key driver of poverty and inequality in this country.

In a statement, Facebook blamed “technical failure” for ProPublica’s recent findings and continues to express a desire to get this right. The company now says that all advertisers who want to exclude groups of users from seeing their ads — and not just those advertising housing, credit and employment — will have to certify that they are complying with anti-discrimination laws. And, just yesterday, the company announced that it would temporarily turn off all advertisers’ ability to exclude users by race while it continues to work on these problems.

Still, this story makes the need for greater transparency and accountability from these online platforms that much more urgent. Discrimination in the virtual world is no less damaging than offline discrimination, but it can be even more difficult to root out. People who are excluded from viewing Facebook advertisements, for example, would never know that the housing opportunity existed, and so they would not apply. 

It is the most vulnerable Americans who tend to lose the most from predatory business practices.

What’s worse, unlike in the pre-digital world, where organized communities and advocates could spot discriminatory ads and report them, it is impossible for someone who didn’t see a relevant housing ad to prove that discriminatory targeting is responsible. And of course, it is the most vulnerable Americans who tend to lose the most from predatory business practices.

The good news is that there is a way to find these issues: audit testing by academic researchers. Had Facebook allowed outside researchers to see the system it had created to catch discriminatory ads, those researchers could have spotted the problems and ended the mechanism for discrimination sooner.

There are whole communities of researchers ready, willing and able to conduct the audits that could help protect the public from some of the digital platforms’ most pernicious effects on civil rights. Having learned that it is not well-equipped to police its own systems, Facebook should commit to allowing independent audits. Justice, fairness and civil rights laws demand no less.