The U.S. Supreme Court building. (Leah Millis/Reuters)

The Supreme Court debated Wednesday whether to overturn an important decision written by Justice Antonin Scalia for a unanimous court 22 years ago.

There was a twist.

At the oral argument, it was the late justice’s most devoted conservative acolytes who were anxious to junk Auer v. Robbins, which says judges generally should defer to a federal agency’s interpretation of its regulations.

It was the liberal justices who were vociferous in their unwillingness to let Auer go without a fight, saying it was an essential component of judicial humility and deference to expertise.

“I want to parody it, but, I mean, this sounds like the greatest judicial power grab since Marbury versus Madison,” said Justice Stephen G. Breyer, referring to the 1803 decision that established the principle of judicial review of federal laws.

He added, to laughter: “Which I would say was correctly decided.”

What has changed since Scalia’s 1997 decision is a growing concern in conservative legal circles that what is called “Auer deference” and other doctrines like it give too much power to government agencies, who use it to the detriment of business, regulated industries and ordinary people.

Justice Clarence Thomas several years ago said Scalia once told him that Auer was a terrible decision. “You wrote it!” Thomas reminded him.

Paul W. Hughes, representing a military veteran who objected to a Department of Veterans Affairs decision regarding disability benefits but lost in federal court, told the justices they should overturn Auer and a case decided in 1945, Bowles v. Seminole Rock and Sand Co.

The decisions give too much power to agencies, which can change regulations without adequate public notice and comment, Hughes said.

“That is not just some speed bump along the administrative process,” Hughes said. “This matters as a practical matter a great degree.”

Home builders and manufacturers are among those asking the court to get rid of Auer, saying that changes in administrations lead to shifts in how agencies interpret regulations and open them to new liability. Those rules can cover areas including workers’ tips and environmental standards.

“Given the breadth of federal regulations, virtually every business in America, large or small, has at least some portion of its work regulated by federal agencies,” said a brief filed by the U.S. Chamber of Commerce.

The liberal justices said safeguards already exist.

“We made it plain that Auer does not call for blind deference,” said Justice Ruth Bader Ginsburg. “The court must, first of all, agree that the regulation is, indeed, ambiguous and that the agency interpretation is a reasonable one.”

Justice Elena Kagan said the Auer decision’s underpinning “is an idea that judges are far less suited to make these kind of minute decisions of agency policy than agency decision-makers are.”

Justices on the left are on guard that the court’s conservative majority is trying to make it easier to overturn precedent. Kagan said that, usually, a precedent remains in place unless it is “so grievously wrong that we can’t stand to live with it anymore.”

There was no evidence of that here, she said, plus Congress has been free to step in ever since the decisions were made decades ago.

For once, the liberal justices were more aligned with the Trump administration’s solicitor general, Noel J. Francisco. He said the precedents should remain in place but judges should do more to employ standard review procedures and ensure the regulation in question was genuinely ambiguous.

Francisco’s biggest antagonist was Justice Neil M. Gorsuch, who in the past has said deference to agencies threatened the separation of powers.

“There are six elements of your test,” Gorsuch told Francisco. “We have to decide whether the regulation is ambiguous, whether the interpretation is reasonable, whether it’s consistent, whether it was made by someone at a high level, whether there was fair notice, and whether it was made by somebody with expertise.”

Is that “a recipe for stability and predictability in the law, or is that a recipe for the opposite?” Gorsuch asked.

The alternative, Francisco said, was having many district judges interpret the regulation, which would not be good for anyone, including the regulated parties.

Gorsuch responded: “ I must say I cast a skeptical eye when the government is worried about private reliance interests.”

Justice Samuel A. Alito Jr. noted that the word being dissected in veteran James L. Kisor’s case was “relevant” and wondered why a judge wasn’t just as capable of defining that as someone in the Department of Veterans Affairs.

Chief Justice John G. Roberts Jr. and Justice Brett M. Kavanaugh seemed to be exploring ways to alter Auer without explicitly overruling it.

The case is Kisor v. Wilkie.

Correction: An earlier version of this story mididentified Paul W. Hughes. It has been corrected.