A divided Supreme Court appeared reluctant Tuesday to undo the Trump administration’s decision to end an Obama-era program that gives nearly 700,000 so-called Dreamers the ability to work in the United States and avoid deportation.

During more than an hour of oral arguments, attorneys for challengers told the justices that the Department of Homeland Security — while it has the authority to end the discretionary program — did not adequately explain why the administration chose to do so.

[Immigrant ‘Dreamers’ look to Supreme Court, Congress for help]

The Supreme Court decision, expected before the end of the term in late June, has the potential to reshape the nearly two-decades-old push in Congress for more permanent protections for immigrants who arrived in the United States as children.

The Trump administration had determined the Obama-era policy was unlawful and unconstitutional and revoked it in September 2017, although no court had ruled so. The department later expanded on those reasons in a memo filed in one of the three lawsuits the Supreme Court is reviewing.

[Supreme Court cases could stir politics on ‘Dreamers’]

Theodore Olson, who argued on behalf of Dreamers, and Michael Mongan, who argued on behalf of the state of California, told the justices that even that later memo relies too much on the idea that the program was illegal.

The Trump administration’s decision to end the program, if allowed to stand, means Dreamers would lose the ability to work and could be deported to countries they left at such a young age that they may not even remember them. It was a political decision, Olson said.

Blaming the legality of the program avoided political heat, Olson said: “The administration did not want to own this decision.”

Mongan added that the public doesn’t know what the government would do if it couldn’t use the law as a scapegoat, since “the administration has expressed broad sympathy for this population, and they very well might continue the policy or stop short of wholesale termination.”

Questions from justices in the court’s liberal wing suggested they think the department should have to more fully explain the decision to the people, employers, military organizations, states and companies who have relied since 2012 on the Deferred Action for Childhood Arrivals program, known as DACA.

Justice Ruth Bader Ginsburg said the whole DHS memo is “infected” by the idea that DACA was unlawful. And Justice Sonia Sotomayor was forceful in pointing out that President Donald Trump had told Dreamers that they were safe under his presidency, but the reasons why that turned out not to be true are not in the department’s reasoning.

“Where is all of this in the memo?” Sotomayor asked. “And where is the political decision made clearly? That this is not about the law, this is about our choice to destroy lives.”

Solicitor General Noel Francisco, defending the decision for the Trump administration, told the justices that the memo includes reasoning “regardless” of the legality of DACA. He resisted the idea that the administration should have to do it over.

“We own this,” Francisco said, which includes both the policy rationale in the memo and the judgment on DACA’s legality.

Justices on the conservative majority of the court, particularly Justices Samuel A. Alito and Neil M. Gorsuch, raised concerns about whether the courts could review the decision at all.

“What good would another five years of litigation over the adequacy of that explanation serve?” Gorsuch asked Olson.

And Alito said to Olson: “Do you seriously want to argue that if this case were to go back and the agency were to say again” what was in the memo, “that would be unlawful?”

The Obama administration based the DACA program on the idea that it had broad prosecutorial discretion to prioritize enforcement of the immigration laws. Alito suggested that courts might not need to review such a change in prosecutorial discretion.

Justice Brett M. Kavanaugh repeatedly asked the challengers why the DHS memo did not adequately cover other reasons for the administration decision.

“I mean, this is a serious decision. We all agree with that,” Kavanaugh said. “And to say in writing even if it’s lawful, I nonetheless am going to exercise my discretion, I assume was a very considered decision.”

And Chief Justice John G. Roberts Jr. asked Mongan how much the government needs to explain its reasons, and how much more it would need to say if the Supreme Court required it to do it over.

For example, Roberts pointed out that the Trump administration cited a legal challenge to President Barack Obama’s expansion of DACA that was struck down by federal courts.

“Can’t he just say, ‘That’s the basis on which I’m making this decision?’” Roberts asked.

Sen. Richard J. Durbin, the Illinois Democrat who first introduced an act to protect Dreamers and has a new version this year with South Carolina Republican Sen. Lindsey Graham, was in the public gallery for the argument.

Ahead of the arguments, Trump tweeted that a ruling that backed the administration’s decision to end the DACA program would boost the chances of more permanent protection in legislation.

“If Supreme Court remedies with overturn, a deal will be made with Dems for them to stay!” Trump tweeted of the Dreamers.