The Supreme Court’s decision today upholding the travel ban is wrong—and wrenching—for many reasons. I will focus here on the legal argument that got the least play in the Court’s decision: the claim that the travel ban violated a non-discrimination provision of the immigration law. The Court’s failure to grapple with that mandate, alongside the Court’s deferential review of the constitutional claim, green lights future attempts to reconfigure immigration to America on racial lines.

To recap, the President’s third iteration of the ban, issued in September 2017, banned large groups of immigrants and visitors from eight, mostly Muslim-majority countries. The plaintiffs raised three claims—two statutory and one constitutional—challenging this latest travel ban. The first argument was that the travel ban exceeded the President’s statutory authority, under 8 U.S.C. § 1182(f), to bar aliens whose entry he deemed “detrimental” to U.S. interests. The second claim was that the ban violated a separate provision, 8 U.S.C. § 1152(a), prohibiting nationality discrimination in the issuance of immigrant visas. The third claim charged that the ban violated the First Amendment Establishment Clause by discriminating against Muslims.

The Court majority spent barely four pages on the statutory non-discrimination claim. Essentially, the Court said that, while § 1152(a) prohibits the government from denying immigrant visas on the basis of nationality, it only applies to immigrants who are otherwise admissible to the United States. And because § 1182(f) gives the President broad authority to suspend entry, and the President has done so here, the only immigrants denied visas are those who are inadmissible. In other words, despite an explicit provision forbidding discrimination on the basis of nationality, the President can…ban immigration on the basis of nationality.

The problem with this argument is that it overlooks the entire reason why Congress passed § 1152(a) in the first place: to abolish the racially based national origin quotas that had infected U.S. immigration policy for decades. In 1924, following recurrent agitation against immigrants from Eastern and Southern Europe and Asia, Congress capped immigration from each country at levels proportionate to that country’s representation in the 1890 U.S. population. The purpose was to freeze the racial and cultural composition of the United States. (A separate law, from 1790 to 1952, made only white people eligible for naturalization). After decades of reform efforts, Congress passed the landmark 1965 Immigration and Nationality Act specifically to repeal the national origins quotas that had by then become a stain on the U.S. image around the world. In what is now § 1152, Congress stated that “no person shall…be discriminated against in the issuance of an immigrant visa because of the person’s race, sex, nationality, place of birth, or place of residence.”

When it passed this non-discrimination mandate, Congress made no exception for discrimination by the president pursuant to 1182(f). And for good reason: it would make no sense for Congress to ban national origin quotas but allow a president to reinstate an indefinite ban on certain nationalities under 1182(f). Such allowance would contradict the very purpose of the 1965 law.

Fast forward to 2018. Beyond Muslims, this President has made no secret of his disdain for other racial groups and nationalities—Mexicans whom he deems “rapists,” Central Americans whom he calls “animals,” and Africans from what he describes as “shithole countries.” When he made the last of these remarks, the President asked why the United States couldn’t bring in more immigrants from “places like Norway.”

In Trump v. Hawaii, the Court set no limit on the president’s ability to exclude such groups on the basis of race or nationality, so long as he claims their entry would be detrimental to the United States for some foreign policy or national security reasons. It is not difficult to imagine the administration raising foreign policy or national security objections to these groups’ entry, whether premised on a country’s perceived slights to the United States or the depiction of its nationals as public safety threats.

The “highly constrained” standard that the Court applies to plaintiffs’ constitutional objections to the travel ban compounds the problem. The Court rules that the exclusion order should be upheld so long as it meets a highly deferential standard of rational basis review, and observes that “it should come as no surprise that the Court hardly ever strikes down a policy” under that standard. While the Court leaves open the possibility of rejecting a policy with no “relationship to legitimate state interests” or one that is “inexplicable by anything but animus,” the Court’s application of that standard to the travel ban suggests that few exclusions, if any, will fail such scrutiny.

Indeed, the Court provides a detailed roadmap for the return of racial origin quotas. Based on its decision, an administration choosing to ban, say, Mexicans, Central Americans, or Africans, need only do the following: 1) identify a legitimate objective, such as vetting nationals or deterring crime; 2) draft an order that cites that objective to exclude certain nationalities, while making no explicit reference to race; 3) leave out some countries from the order that are racially similar to the groups excluded, and include others that are not, to avoid the appearance of bias; 4) generate a secret report based on a “worldwide” multi-agency review that purports to justify the country selection; 5) exempt some categories of immigrants from certain countries to appear less arbitrary; 6) allow for individual waivers, at least in theory; and 7) after the order is issued, make small modifications to appear responsive to changed conditions. As long as the administration does that, the President should feel free to dehumanize and race-bait all he wants on Twitter. Today’s decision suggests that five justices of our highest Court will not object. Indeed, they have shown the way.

Shirin Sinnar is Associate Professor of Law and the John A. Wilson Faculty Scholar at Stanford Law School. Her scholarship focuses on the role of institutions, including courts and executive branch agencies, in protecting individual rights and democratic values in the national security context.