The Supreme Court grappled Wednesday with the unusual legal maneuvers the Biden administration used to wipe out a Trump-era immigration rule and whether to let some Republican-led states continue the court fight to save it.

At the heart of the case is the Trump administration’s expansion of the long-standing “public charge” rule, which allowed the Department of Homeland Security to deny green cards to immigrants deemed likely to use more non-cash public benefits.

In 2019, the Trump administration rule sought to expand the types of government benefits whose use could disqualify immigrants from obtaining green cards to include Medicaid, public housing assistance and the Supplemental Nutrition Assistance Program, formerly known as food stamps. Several federal judges ruled against the policy, but the Supreme Court gave the administration reprieve from those court rulings, allowing the rule to take effect.

The oral arguments Wednesday focused not on the merits of the policy, but on the convoluted legal challenges in different federal courts around the country, and what happened when President Joe Biden took office and ordered a new public charge rule.

In short, the Biden administration declined to defend the Trump-era rule in court. That move meant the rule would be vacated by one Illinois federal court ruling, would wipe out two challenges already at the Supreme Court, and would avoid a notice-and-comment process to rescind a rule under the Administrative Procedure Act, known as the APA.

Arizona Attorney General Mark Brnovich told the justices that his state and others should be able to intervene to defend the Trump-era rule in a case out of the 9th U.S. Circuit Court of Appeals, since the federal government won’t defend it. He argued on behalf of 12 other states that joined the case.

“Ultimately, if you allow the actions of the Department of Justice to stand in this case, it sets a dangerous precedent for future administrations to essentially do an end around the APA,” Brnovich said.

Chief Justice John G. Roberts Jr. was among those who picked up on those concerns. He said the court has “to think long and hard before adopting a rule that allows any administration to circumvent notice and comment rulemaking before the repeal of a rule.”

But there was skepticism from across the bench about whether Arizona had a right to intervene in a case from California, in what Justice Elena Kagan called a “quadruple bank shot” strategy to revive the Trump-era rule because it would involve several steps across several courts across the nation.

Brian Fletcher, the principal deputy solicitor general who argued for the government, told the justices allowing the states to intervene in the California case would undercut Congress’ decision to give the Justice Department the power to decide whether to appeal decisions that go against the government. Such a decision is not uncommon, Fletcher said.

“Here, DHS had decided to issue a new public charge rule, the ongoing litigation would have complicated that rulemaking and required intrusive discovery, the 2019 rule was not producing its intended effects, and the rules’ unintended and unwanted effects were aggravating a public health crisis,” Fletcher said.

The Biden administration issued a notice in August of plans for a new rule. Last week, it unveiled details of its new proposal, which would reverse the Trump-era rule.

[Proposed rule nixes Trump interpretation of ‘public charge’]

“This is not a circumvention of notice and comment regulation,” Fletcher said. “DHS is engaged in notice and comment rulemaking that the states will be free to participate in to make a new public charge.”

The Supreme Court will issue an opinion in the case by the end of the term at the end of June.