The Ninth Circuit grappled with the president's tweets and agency discretion during oral arguments on the administration's decision to rescind the Obama-era immigration policy known as Deferred Action for Childhood Arrivals.

U.S. District Judge William Alsup of the Northern District of California partly blocked the Trump administration's decision in January, ordering the government to continue processing renewal applications for existing DACA recipients. The Supreme Court later rejected an appeals request by the Justice Department, sending the case back to the Ninth Circuit.

During Tuesday's arguments, Justice Department lawyer Hashim Mooppan questioned the court's reviewability of the rescission, while three different lawyers for plaintiffs urged the judges to affirm the lower court's finding that the rescission was likely “arbitrary and capricious.”

Covington & Burling partner Jeffrey Davidson argued pro bono on behalf of the Regents of the University of California system, California Deputy Solicitor General Michael Mongan argued for the state and Public Counsel Director Mark Rosenbaum argued for the individual plaintiffs.

Here are four key takeaways from the oral arguments before the U.S. Court of Appeals for the Ninth Circuit on Tuesday:

Courts' Ability to Review DACA Remains a Big Question

The first part of oral arguments centered around the government's claim that the Trump administration's DACA rescission is not reviewable by courts because it's a “discretionary enforcement decision.” Judges Jacqueline Nguyen and Kim McLane Wardlaw—both Obama nominees—pushed back.

Wardlaw pointed out that then-acting Department of Homeland Secretary Elaine Duke's “decision to rescind appears to be based entirely on” a letter from U.S. Attorney General Jeff Sessions. That letter suggested the Fifth Circuit's finding in 2015 that Deferred Action for Parents of Americans was unlawful, and should contribute to DACA's rescission.

“If that is wrong as a matter of law, which is as Judge Alsup said, a question essentially for the courts, can the decision to rescind stand?” Wardlaw asked. Mooppan maintained the matter was still nonreviewable.

Wardlaw also urged Mooppan to square how the Fifth Circuit found DAPA to be reviewable, but not the wind-down of DACA. Mooppan said the Fifth Circuit found that DAPA “so exceeded the congressional scheme that it ceased to be a valid prosecutorial discretion policy.”

Concerns Over Equal Protection Clause

While Alsup granted a nationwide injunction on the basis that plaintiffs would succeed on their claims that the rescission was “arbitrary and capricious” under the Administrative Procedure Act, Owens raised the question of whether the court could consider the equal protection clause.

“Let's say that I have concerns over justiciability on the APA claim. But let's say I think your equal protection clause claim is strong. … If we were to say APA is a loser but motion to dismiss—Judge Alsup got that right—procedurally where are we in this case?” Owens said.

Rosenbaum argued the court could affirm the injunction on Equal Protection grounds too.

The exchange raised more questions about Trump's tweets and past statements about DACA recipients. In his follow-up, the DOJ lawyer said the DHS secretary was ultimately responsible for the decision to rescind DACA, which Owens pushed back on.

“At a minimum, [plaintiffs' lawyers] have to have clear evidence of discriminatory intent. They don't have a single allegation in their complaint about the acting secretary's motive in this case,” Mooppan said.

Owens pushed back on that notion.

“Right, but the acting secretary ultimately reports to the POTUS and he has said all kinds of things that could be relevant in this litigation,” he said, before acknowledging the panel would have to wait for the Supreme Court's ruling in the travel ban case to fully evaluate such statements.

DACA Lawful, and a Litigation Risk?

The DACA rescission memo remained an issue for the panel, with the judges squarely asking both sides whether DACA was lawful. The Justice Department lawyer maintained it was not, but that the Trump administration's reasoning for rescinding DACA also included the risk of litigation.

Mongan, representing the state of California, disagreed that DACA was unlawful—but he added he was not sure whether the “litigation risk was reasonably discerned in the memo.” Even if it were, it would not affect its reviewability, he said.

DOJ Considering Redoing DACA Rescission Memo

Nguyen also asked Mooppan whether the Justice Department—in light of a recent decision by U.S. District Judge John Bates of the District of Columbia—would redo its DACA rescission memo.

Bates enjoined the Trump administration's DACA wind-down in April, ordering the United States to resume accepting applications for both new and existing DACA recipients. But he gave the government 90 days to issue a new memo before his injunction went into effect.

Mooppan replied that a re-do of the rescission memo was something the administration was still considering. “We're actively considering it, but we of course think the Duke memo is itself sufficient … we're actively considering what to do in light of the” Bates opinion.

Read More:

Trump Administration Set for Third Appeal Over DACA Suit to Head to Second Circuit

Why Judge John Bates Embraced 'Undocumented' Over 'Illegal' in DACA Ruling

Trump's Statements Focused On, Propelling DACA Suit Forward

Trump's Newest Tweet Target: Solicitor General Noel Francisco