No, President Trump’s order curtailing entry to the United States from seven Muslim-majority countries is not the “total and complete shutdown” he threatened in December 2015, but it’s bad enough.

Even after the dust settles from its spectacularly mishandled early days, even after the administration patches up its worst flaws — such as the exclusion of green-card holders and those who aided U.S. troops in the Middle East — the measure recasts the United States as a country so fearful of an admittedly serious terrorist threat that it would retreat from its most generous traditions.

In a world where millions seek haven from war and repression, Trump’s order suspends refu­gee admissions for 120 days, even for those already thoroughly vetted and approved, and slashes them thereafter from the previous target of 110,000 in fiscal 2017 to 50,000.

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Whether this bad policy is unconstitutional, or even illegal, however, is a different issue — and not an easy one.

(Peter Stevenson/The Washington Post)

The basic problem facing the various states and private plaintiffs now flocking to federal court is that the president enjoys extremely wide authority over immigration matters.

Under the 1980 Refugee Act, the president decides how many refugees the United States will resettle on U.S. soil each year, which is why President Barack Obama could crank the target up from 85,000 in fiscal 2016 to 110,000 in fiscal 2017.

Trump’s order invokes an even broader statutory provision that allows the president to restrict or suspend the entry of “any aliens or . . . any class of aliens” whose admission he deems “detrimental to the interests of the United States,” for pretty much as long as he thinks is necessary.

Historically, courts have been deferential toward presidents’ exercise of this authority, both because Congress’s delegation is so clear and because of the judicial branch’s traditional, and usually well-founded, reluctance to weigh in on matters affecting foreign affairs and national security.

The still-forming constitutional case against Trump’s order does not, therefore, deny his broad power. The argument would be that he has abused it — exercised it in violation of the religious freedom clause of the First Amendment — by imposing criteria that disfavor Muslims and favor Christians, without showing any actual connection to a policy goal, or making any attempt to achieve that goal though less restrictive alternatives.

“It can’t be an across-the-board blunderbuss,” says David Cole, national legal director of the American Civil Liberties Union.

This amounts to a demand that courts flunk Trump’s order under the doctrine of “strict scrutiny” that applies to potentially discriminatory measures in the domestic arena.

The problem is that they have never said anything like that before regarding immigration. To be sure, Trump’s own prejudiced remarks about Muslims undermine his claim to be acting rationally and impartially in the national interest. It will certainly be interesting to watch administration lawyers try to defend their boss’s words, or explain them away, when judges start grilling them in open hearings.

However, the fact that the order is only temporary, and could result in nothing more than tweaked procedures, could mitigate that ugly history; what’s more, the actual text makes no reference to Muslims per se.

Trump has made it plain in various comments that he intends to help Christians toward whom, he alleges, the previous administration was indifferent.

But, again, the order’s text instructs the bureaucracy to “prioritize” — whatever that means — future refu­gee claims from “minority” religions, implying Middle Eastern Christians without saying so expressly. That leaves the door open to Yazidis, Bahais and even Shiite Muslims from majority-Sunni countries.

No doubt even that reading entangles the executive branch in the questionable business of defining “majority” and “minority” religious denominations, and choosing among them. However, courts might well worry that once they start supervising those decisions, they’ll never be able to stop.

Like other wide congressional grants of authority to the executive branch — the power to levy “emergency” tariffs comes to mind — the vast discretion over immigration Trump has inherited was a product of a different time.

Lawmakers during the post-World War II era assumed presidents of both parties agreed on certain broad lessons of prewar history, such as the need to remain widely engaged through trade and collective security, and the importance of humanitarian values — “soft power” — in U.S. foreign policy.

They did not anticipate today’s breakdown in national consensus, much less that heirs to the America Firsters who had failed to attain national power before World War II could ever attain it afterward.

The judicial protection that plaintiffs seek from Trump’s executive order may be unprecedented; if so, that’s partly because the violations they allege were once unimaginable.

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