The Trump administration’s immigration agenda may be imperiled by the president’s own U.S. Supreme Court appointees.

A case taken up by the court has the potential to overturn or severely limit a legal doctrine, disliked by many conservative jurists, that gives power to federal agencies when there’s a dispute over how they interpret regulations. The principle has been questioned by four of the high court’s nine justices, including Neil M. Gorsuch and Brett M. Kavanaugh, and any change in the amount of scrutiny that courts give to those interpretations will have particular significance in cases involving business immigration.

The outcome has particular implications for technology companies that recruit heavily through the H-1B skilled guest-worker program, a target of U.S. Citizenship and Immigration Services policy memorandums that take a more restrictive view of what qualifies for the visas. The new policies implement President Donald Trump’s Buy American and Hire American executive order.

Businesses are already gearing up to sue the administration over what they view as unduly restrictive immigration policies. Two lawsuits have been filed over a USCIS policy requiring employers that place their H-1B workers at third-party sites to provide details of all their work for the full three-year term of the visa.

Those lawsuits could grow exponentially if the law is no longer tilted in the administration’s favor.

“The prospects of winning will be greater,” so businesses will be even more likely to sue, Chad Blocker of Fragomen, Del Rey, Bernsen & Loewy told Bloomberg Law.

“I do think it could have a significant impact” on lawsuits challenging immigration policy, Thomas Ragland of Clark Hill in Washington told Bloomberg Law. Eliminating the doctrine wouldn’t necessarily make it easier for companies to sue the government, but “it makes the government’s argument harder,” he said.

Arguments in the case likely will take place before May, with a final decision from the Supreme Court expected before the end of June.

‘Thumb on the Scale’

Known as Auer or Seminole Rock deference, the doctrine says courts should credit an agency’s interpretation of its own regulations if those regulations are ambiguous, even if there’s more than one reasonable interpretation. The doctrine, along with Chevron deference—which credits agencies’ interpretations of laws passed by Congress—has come under scrutiny by some judges and justices.

Auer deference has helped federal agencies in “borderline” cases, providing the “thumb on the scale” that tips the case in favor of the agency’s interpretation, said Ragland, who previously worked for the Justice Department. Without that doctrine, “the playing field is no longer tilted” in favor of the government; “it’s level,” he said.

If the government can convince the court that its interpretation is reasonable without relying on Auer, “then good for them, they deserve to win,” Ragland said.

Gorsuch and Kavanaugh, Trump’s two appointees, criticized deference before joining the Supreme Court. Chief Justice John G. Roberts Jr. and Justice Clarence Thomas also have expressed doubts about the doctrines. Deferring to agency interpretations upsets the separation of powers by putting too much power in the executive branch, they say.

Former Justice Anthony M. Kennedy also raised eyebrows when he wrote an opinion calling deference into question in a deportation case. The majority opinion from Justice Sonia Sotomayor avoided the issue by finding that the law wasn’t ambiguous.

Litigation Targets

Several USCIS policies could face additional scrutiny if courts no longer defer to the agency’s regulatory interpretations.

In addition to the H-1B third-party placement policy, they include a policy that redefines how foreign students accrue “unlawful presence,” a policy on when the USCIS can issue “notices to appear” in removal proceedings, and a policy allowing the agency to deny visa petitions without first requesting more evidence.

Businesses also are likely to sue over an increase in visa denials that aren’t linked to official policies, such as denials based on the wages being offered to H-1B workers.

But what replaces deference, if anything, could determine the outcome for immigration cases, Jill Family, a professor at Widener University’s Commonwealth Law School, told Bloomberg Law.

Courts could rely on what’s known as the “Rule of Lenity,” which resolves ambiguities in the law in favor of immigrants, she said. On the other hand, courts have tended to defer to Congress and the executive branch on immigration issues, she said.

Or there could be different levels of deference depending on the immigration case, such as whether it involves removal versus denial of a visa, Family said.

Another “very likely outcome” is that the agencies start churning out more regulations, Blocker said. The courts “could just require that if there’s vagueness or lack of clarity in a regulation, that the agency go through the formal rulemaking process to clarify the ambiguity,” he said.

Even that isn’t a cure-all, Blocker said. “It’s not reasonable to think that Congress or federal agencies are going to be able to contemplate every variation of every fact pattern that may come up,” he said.