The U.S. Supreme Court's conservative majority signaled Tuesday that it may let the Trump administration shut down the Obama-era program that granted temporary protection from deportation to roughly 700,000 young people, commonly known as DREAMers.

Brought to the U.S. illegally as children, the DREAMers were allowed to legally work and go to school if they met certain requirements and passed a background check. The program, begun in 2012, is known as DACA — Deferred Action for Childhood Arrivals.

Until Tuesday the administration had consistently maintained that it had no choice but to pull the plug on the program because, as President Trump's attorney general put it in September 2017, the DACA program was "illegal" and "unconstitutional" from the time it was first put in place in 2012.

Three federal appeals courts disagreed and ruled that when an administration revokes a policy like this, on which so many people, businesses and even the U.S. economy have relied, the administration must provide a fully supported rationale that weighs the pros and cons of the program, the costs and the benefits. Faced with those lower court decisions, the Trump administration appealed to the Supreme Court, which seemed Tuesday to be on the verge of a contrary decision.

Can the Supreme Court even decide this case?

Solicitor General Noel Francisco opened the argument, telling the justices that they have no authority to review the policy change because DACA is a discretionary program under which the Obama administration used its prosecutorial discretion to defer deportations for certain qualified individuals.

The court's liberals pushed back. "There's a strange element to your argument," Justice Ruth Bader Ginsburg told the solicitor general. She pointed out that he was arguing that "this is a discretionary matter" and therefore "not reviewable because it's committed to agency discretion. But on the other hand, you say the agency had no discretion because this program was illegal.... So how can it be committed to your discretion when you're saying 'we have no discretion'?"

Ginsburg said that even a second memo, written after the litigation began, was "infected" with the idea that DACA was illegal.

Justice Sonia Sotomayor pointed to Trump's conflicting remarks about DACA recipients, noting that the president told the DREAMers that they were "safe under him" and then abruptly ended the program.

"We own this"

But when the lawyers representing the DACA plaintiffs rose to argue, they got a fusillade of doubt from the conservative wing of the court.

Chief Justice John Roberts sought to minimize the number of immigrants covered by previous programs similar to DACA, dating to the 1950s. Other members of the conservative majority fired different rounds.

Justice Samuel Alito posed this hypothetical: Let's say an administration decides not to prosecute drug cases involving less than 5 kilos of cocaine, and the next administration decides to change the amount to 3 kilos. Would that be reviewable by the courts?

Lawyer Theodore Olson, who represented the plaintiffs, replied that DACA is different because of the huge number of people and industries and businesses that have relied on the assurances in the existing program. If the government wants to change such a program, he said, it has to lay out its policy reasons, and not just by fiat say that the DACA policy was illegal from the get-go.

"What more would you have the government say?" interjected Justice Neil Gorsuch. "What good would another five years of litigation over the adequacy of the explanation serve?"

Replied Olson: "We don't know what the administration would do." The Trump administration "did not want to own this decision." It was not an independent decision reached by the acting secretary of homeland security because DHS was bound by the attorney general's one-sentence decision saying DACA was illegal, Olson said.

In rebuttal, Francisco, the Trump administration lawyer, batted that down, saying the administration has decided that even if DACA was and is legal, Trump has decided to shut it down.

"We own this," he said.

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