By upholding President Donald Trump’s travel ban (in its third iteration) in Trump v. Hawaii on Tuesday, the Supreme Court did Trump an enormous favor: It pretended he didn’t exist.

Chief Justice John Roberts’s majority opinion (signed onto by the Court’s three other conservatives and “swing vote” Anthony Kennedy) is a clear declaration that the executive branch had the legal power to indefinitely restrict certain visa holders and immigrants from several countries, as the current travel ban (signed in September) has done since it was allowed to go into effect in December. The opinion scrupulously avoids any defense of Donald Trump, as an individual, in deciding to order such a policy.

But by ignoring Trump, the Supreme Court has sent a different message: that nothing Trump is doing is more damaging to the presidency than what the Supreme Court would do if it tried to restrain him.

“We must consider not only the statements of a particular President, but also the authority of the Presidency itself,” Roberts wrote in his opinion. And ultimately he declined to do anything that could damage the latter.

This is typically the way the Supreme Court does things: It rules on matters of law, not policy; it devises broad rules that can govern institutions no matter what individuals are running those institutions.

That doesn’t mean it’s the only way to make decisions, or even the right way. And it runs the risk that the Court will deliberately blind itself to the evidence that a president is, himself, a threat to the presidency.

The various opinions on the travel ban showed that many justices on the Court are wrestling with this, or at least aware of it. Justices Sonia Sotomayor and Ruth Bader-Ginsburg wrote a dissent that included all the presidential statements Roberts and company deemed irrelevant; Justice Kennedy, in a concurrence, basically begged Donald Trump not to say bigoted things when the Court couldn’t sanction him for them.

Even Roberts himself, by going out of his way to reject the Court’s 1944 decision in Korematsu v. United States that paved the way to the detainment of Japanese Americans, recognized that sometimes the Supreme Court isn’t capable of seeing when the threat to the rule of law is coming from inside the house.

Upholding the travel ban was a refusal to limit the power of the executive branch because of the hypothetical future danger

It’s hard to overstate the extent to which Roberts’s majority opinion talks about the presidency as if it’s not currently being occupied by any human at all — or, at least, not by Donald J. Trump, a president who has personally attacked several members of the federal judiciary and was last seen mocking the idea of using “judges and court cases” to help process immigrants who enter the US illegally.

On one hand, Roberts (per usual) deferred to the past: Supreme Court precedents that give the executive branch broad authority not just to set policy when it comes to immigration, but to shield that policy from judicial review.

On the other, his interpretation of those precedents pointed toward the future — the idea that any decision he and the Court made now could obstruct some hypothetical future president from responding to some hypothetical future world crisis. (This was a concern that he and Anthony Kennedy both raised at oral argument, using “ticking time bomb” scenarios in which an overbroad ruling could force the US to allow a terrorist to enter the United States.)

”The upshot of our cases in this context is clear,” Roberts wrote in his opinion: “‘Any rule of constitutional law that would inhibit the flexibility’ of the President ‘to respond to changing world conditions should be adopted only with the greatest caution,’ and our inquiry into matters of entry and national security is highly constrained.”

Ultimately, he concluded, the 9th Circuit’s interpretation of the Immigration and Nationality Act (which allows for the president to suspend the entry of a “class” of people, but also prevents discrimination based on nationality in immigration policy) wasn’t cautious enough. And so, he and the Court overturned the 9th Circuit.

The Supreme Court has committed itself to the belief that the presidency tames the president

The other way that Roberts wrote an opinion upholding Trump’s policy as if Trump wasn’t involved was by assuming that, frankly, Trump wasn’t.

Roberts’s opinion, following the cue of Solicitor General Noel Francisco (who argued for the travel ban at oral argument for the case in April), relied heavily on the idea that the current version of the travel ban wasn’t Donald Trump’s policy, but instead “reflects the results of a worldwide review process undertaken by multiple Cabinet officials and their agencies.”

Because that policy process was normal, Roberts ruled, the Court lacked the authority to plumb too deep into what might have motivated Trump to ask for the process. The bureaucracy cleansed the travel ban of its Islamophobic “taint.”

Not since the first version of the travel ban has the Trump administration tried to argue that it would be constitutional for President Trump to implement the “Muslim ban” that candidate Trump promised. Instead, they’ve argued, assuming the presidency — and the authority to uphold the Constitution that came with it — washed away any Islamophobic impetus for a travel ban, and left solely the desire to protect the United States from people who might take advantage of insufficient passport requirements from certain countries.

In other words, the government argued that the presidency tamed the president.

The Supreme Court didn’t need to go that far. And in fact, Justice Kennedy’s concurrence all but acknowledged that it hadn’t tamed Trump: Kennedy’s beseeching of officials to uphold the Constitution in their words and actions, even when the judiciary can’t do anything to force them to, was such an obvious subtweet that not actually naming Trump felt unnecessarily coy.

But Kennedy agreed with Roberts that whatever Trump as an individual is saying and doing, it is not seeping into the actions that his government takes that are within the purview of judicial review — the official actions of the executive branch.

What about all the evidence that the president is infecting the presidency?

The problem is that this logic can easily curl back in on itself. The Supreme Court is more worried about the presidency than the president because it doesn’t have any evidence that the president is a problem; the Supreme Court doesn’t have any evidence that the president is a problem because it assumes he’s been tamed by the presidency.

This isn’t limited to Trump or to immigration. The Supreme Court is struggling on a lot of levels with the tension between making decisions based on jurisprudence, where all rules must be neutral and universal, and making decisions based on the understanding of what is actually happening in the real world on the basis of those rules.

In the travel ban case, ruling for Trump required Roberts to write off not just Trump’s statements as a candidate but his tweets as a president, crowing over calling the travel ban a “ban” and ruing that he’d ever let his Department of Justice withdraw the overbroad first version.

It also required them to overlook the fact that at oral argument, Solicitor General Francisco implied that Trump had made amends to Muslims by making it “crystal-clear on September 25th that the president had no intention of imposing a Muslim ban,” when no such September 25 statement existed; that the Justice Department’s clarification cited a January 2017 statement instead that didn’t make it “crystal-clear” at all, much less apologize to Muslims; and to ignore the fact that Trump himself was asked by a reporter on April 30 if he would like to apologize to Muslims, and replied, “There’s nothing to apologize for.”

It required them to overlook the fact that a few hours after Francisco promised that the travel ban was based on a complex interagency review that had nothing to do with religion, White House press secretary Sarah Sanders refused to say that the travel ban wasn’t a Muslim ban.

And it required them to overlook the facts that have come out about the waiver process for immigrants from banned countries. Over the months that the latest ban has been in effect, it’s been incredibly rare for applicants to be granted waivers, even in extreme cases that would justify discretion (like a 10-year-old with cerebral palsy), and that even those who get waivers don’t necessarily get allowed into the country after all. And sworn testimony from consular officers, obtained and posted by Slate, has shown that the officials responsible for granting waivers were told that their job was to find reasons not to grant them.

None of these are facts that the Court had to consider. In fact, some of them are facts that weren’t included in the official record of the case but came out in the news as the justices were deliberating. To use them as the basis for a decision would be, in some ways, a break with Supreme Court tradition.

But, of course, they were allowed to consider the facts. Sotomayor and Ginsburg, in their dissent, did just that. And considering the facts together, they arrived at the conclusion that the institutions — the constitutional obligations of the office of the presidency, the supposedly neutral bureaucratic processes of Cabinet departments — had not only failed to constrain the president, but were furthering his outlook.

It’s hard to see threats in real time — especially if you shut out relevant information

The irony of the travel-ban ruling is that it represents the first time the Supreme Court has denounced its most infamous decision of the 20th century, in Korematsu, as “clearly wrongly decided.”

It’s not just ironic that Roberts did that while ruling for the government in a case that’s been compared to Korematsu — that’s obviously why he did it. Sotomayor and Ginsburg referred to Korematsu in their dissent, and Roberts took the preemptive opportunity to distance the Court, with the safety of seven decades of hindsight, from the grotesquery of confining thousands of American citizens on “national security” grounds.

But of course the grotesquery of Korematsu is obvious in hindsight. In hindsight, the reality of the policy is so monstrous that it blots out the government’s arguments in favor of internment at the time — arguments that were also about national security rather than race, and were, therefore, ostensibly neutral.

Internment wasn’t neutral. It was racist. And there was plenty of evidence for that at the time. But by making a decision to limit what it saw, the Supreme Court made a decision to err on the side of accepting things as normal that clearly were not.

The Court made decisions based on the powers of institutions — the presidency — instead of the people who inhabit them — Donald J. Trump. It made that choice. By doing that, it deliberately blinded itself to noticing when the people are a bigger threat to the institution than legal restraints on it would be.