WASHINGTON ― At the Supreme Court podium in January, lawyer Neal Katyal was hit with a series of questions about a curious phrase in the case law.

The justices wanted to know who came up with the legal standard “merely more than de minimis” ― a phrase that could undercut protections for students with disabilities across the country. If upheld, the standard would reduce the educational benefits those children are promised under the federal Individuals with Disabilities Education Act.

“What’s the origin of this phrase, ‘More than de minimis’? Who thought this up?” asked Justice Samuel Alito. The law generally defines “de minimis” as being so small as to be legally insignificant.

“Who invented it?” asked Justice Ruth Bader Ginsburg, noting that it isn’t found in the Supreme Court’s leading precedent on states’ responsibilities under the IDEA.

While Ginsburg was setting up her question, Justice Elena Kagan jumped in to emphasize the word “merely” — as if to underscore that the standard Katyal was defending is indeed a low one.

The accomplished appellate attorney, who is representing a Colorado school district in the dispute, said the standard was developed over time by the lower courts. But he might have nailed the response if he’d simply pointed to a judge who was key to advancing the standard: Neil Gorsuch.

Judge Gorsuch, who is now President Donald Trump’s eminently qualified Supreme Court nominee, used “merely ... more than de minimis” in a 2008 ruling. While it was not the first time that phrase was applied to the IDEA, a number of courts have found the law demands greater help for students with disabilities.

Gorsuch’s decision in the U.S. Court of Appeals for the 10th Circuit is the touchstone for Endrew F. v. Douglas County School District, the case the justices heard in January and will likely decide by the end of June.

Win McNamee/Getty Images Just as Supreme Court nominee Neil Gorsuch prepares for his confirmation hearing, the justices are pondering a case that challenges his past work.

After this article was first published, Katyal, who came out in support of the Gorsuch nomination on the day it was announced, pointed out on Twitter that the word “merely” was used in a 1990 case from another federal circuit court.

At the time, the courts were grappling with the Supreme Court’s early guidance on the level of educational benefit required by the IDEA. That year Congress responded to the confusion and advances in research with substantial updates to the law, whose protections were strengthened again in 1997 and 2004. Gorsuch didn’t explicitly rely on the 1990 case in his 2008 opinion.

Those legislative updates underscore why advocates and parents of students with disabilities are watching the Endrew F. case closely. The dispute could, for the first time in more than 30 years, clarify the benchmark that schools must meet when drawing up individualized education plans for kids under the IDEA.

The federal law, as it’s been updated, is designed to ensure that children with disabilities have the opportunity to receive a “free appropriate public education.” One of the complexities comes in determining what constitutes an “appropriate” education for kids with more disabling conditions.

Some appeals courts have set a higher standard: Schools must provide the children with a “meaningful educational benefit” that allows them to thrive in school. At least five of the federal circuit courts take a more modest approach: The educational benefits contemplated in students’ individualized plans need only be more than trivial ― the “more than de minimis” test.

But in the six states covered by the U.S. Court of Appeals for the 10th Circuit, including Colorado, the bar is even lower: merely more than de minimis. Or the bare minimum.

The standard “has the effect of depriving children with disabilities of the benefits Congress has granted them by law,” the Obama administration told the Supreme Court last year in a brief urging the review and ultimate rejection of the 10th Circuit standard in the Endrew F. case.

The 10th Circuit had already adopted a low bar in 1996, when it first embraced “more than de minimis,” according to Jack Robinson, the Colorado lawyer representing the child at the center of the Supreme Court case. But Gorsuch’s 2008 opinion added the qualifier “merely,” he said. And as noted, the IDEA has been changed since the 6th Circuit used “merely more than de minimis” in 1990.

That may explain why Alito, Ginsburg and Kagan were mystified by the phrase. No version of the term appears in Board of Education v. Rowley, the 1982 Supreme Court case that set the IDEA baseline which the justices are now trying to clarify.

Courtesy of Jeff Perkins Luke, pictured here with his father Jeff Perkins, was at the center of a disability rights case.

Gorsuch “took some wording from a previous case, but then he added his own twist,” said Jeff Perkins, whose son Luke’s struggles with autism gave rise to the 2008 case in the 10th Circuit. Perkins opposes the Gorsuch nomination and is expected to testify before the Senate Judiciary Committee next week, when confirmation hearings begin.

Robinson had represented the Perkins family a decade ago, when their case, Thompson R2-J School District v. Luke P., went before a three-judge panel including Gorsuch.

Luke’s parents sued the Colorado school district because it had refused to reimburse them after they moved their son to Boston Higashi School, a specialized residential facility for children with autism. Such private school placements, paid for by the public school district, are allowable under the IDEA in limited circumstances.

It’s not that the school district wasn’t doing what it could to meet Luke’s educational needs. As Gorsuch put it, his “life away from school during the same time paints a much different picture.” Berthoud Elementary, where Luke attended second grade, didn’t seem equipped to prepare him for home life.

“Luke was unevenly tempered, often displaying inappropriate and sometimes violent behavior at home and in public places such as grocery stores and restaurants,” Gorsuch wrote. “He developed various sleep problems ― going to bed at odd hours, waking up frequently at night, and refusing to sleep in a bed. Luke also developed a habit of intentionally spreading his nighttime bowel movements around his bedroom. In addition, although Luke became toilet trained at school by the time he was in first grade, he was not able to transfer this skill to the home and other settings away from school.”

Based on this record, a hearing officer, an administrative judge and a federal district judge agreed in three separate decisions that the school district needed to reimburse Luke’s parents for a private school placement ― which Robinson and Perkins both said made a world of difference for Luke.

“Within a very short period of time, he becomes a functioning human being,” Robinson said. The lawyer added that where a child’s educational plan recommends live-in placement at a specialized school, many school districts simply comply.

How could he have imagined that Congress would pass a law whose goal was such a trivial standard? Jeff Perkins, whose son's case came before Judge Neil Gorsuch

But Gorsuch saw things differently. He led the 10th Circuit panel in reversing those three prior decisions, emphasizing that the IDEA benefits available to children like Luke were “limited in scope.”

“We sympathize with Luke’s family and do not question the enormous burdens they face,” he wrote in the decision, which effectively forced the Perkins family to pay for their son’s education out of pocket. “Our job, however, is to apply the law as Congress has written it and the Supreme Court has interpreted it.”

Gorsuch added that the statute only requires schools to create an individual educational plan that allows a student to achieve “some progress” toward the goals identified in that plan. Or in the judge’s more telling phrase, “merely more than de minimis” progress.

Luke’s case has gained attention from those who, like Luke’s father, oppose the Gorsuch nomination. The National Educational Association, the largest teachers union in the country, cites it in a report critiquing his record on the rights of students with disabilities.

In their decision, Gorsuch’s potential future colleagues could raise the standard he set. The Supreme Court “expressed significant skepticism over the very low bar that Judge Gorsuch’s opinion espouses,” the union report observes.

“If the Supreme Court gives a different signal, that will empower parents to expect more and for school districts to feel that they have to deliver more,” Robinson said.

The judge’s defenders, meanwhile, have argued that he was simply applying the law as the high court understood it in 1982. Liberal Harvard law professor Noah Feldman wrote in a column that Gorsuch’s interpretation of what the IDEA requires was “plausible.”

Today Luke is 22 and has aged out of the special education system. He still lives in Massachusetts. He participates in a work program, goes shopping, eats at restaurants and engages in other activities that likely wouldn’t have been possible without the special school.

“Luke has a good life, and he has a life that he simply would not have been able to have without an appropriate education,” said his father, who still can’t get over the 10th Circuit’s ruling.

“How could [Gorsuch] have imagined that Congress would pass a law whose goal was such a trivial standard?” Perkins wondered.

CORRECTION: This article previously stated incorrectly that Judge Gorsuch was responsible for creating the legal standard of “merely more than de minimis” in reference to the Individuals with Disabilities Education Act in a 2008 ruling. Precedent for such language did exist, as noted in updated language above, even if the earlier decision was not explicitly cited by Gorsuch in his ruling. The article has also been updated to include a response from Neal Katyal and additional information about revisions to the IDEA.