To the surprise of many, on June 26, a unanimous Supreme Court in Kisor v. Wilkie allowed continued, though limited, deference to an agency’s interpretation of its own ambiguous regulatory language. Such deference, enshrined in an earlier Supreme Court opinion, Auer v. Robbins, has long been a target of conservatives who view it as a sop to the worst tendencies of the administrative state. It is considered even worse than Chevron deference – deference to agency interpretation of ambiguous statutory language – which at least involved language that had been passed by Congress. In Kisor, Auer was directly at issue, involving interpretation of a regulation of the Department of Veteran Affairs. With five conservative justices on the Court, many considered this the term when Auer, if not Chevron, was facing certain demise.

Answering the question of whether Auer and its predecessors and progeny should be reversed, four liberal members of the Court said emphatically, No, but expounded at length on a court’s obligations before applying Auer, and then remanded the case. Roberts, C.J., agreed that “overruling these precedents is not warranted.” Four other conservative members joined an opinion concurring in the judgment but opined that “[T]oday’s decision is more of a stay of execution than a pardon.” Significantly, all nine members agreed that this decision did not touch upon the viability of Chevron.

On the merits of this particular case, and for the great majority of regulatory interpretation issues, this case means at most that courts will have to offer significant analysis before simply accepting Auer deference to a challenged agency interpretation. However, as a practical matter, there is truth in all three opinions that in the vast majority of situations, a careful analysis of the regulation’s wording and its origin would produce the same result, deference aside. The plurality diligently recited the many ways in which application of deference should be hemmed in rather than mechanistically applied. Chief Justice Roberts agreed and, while implicitly accepting much of what the conservative opinion said, observed that “there is a difference between holding that a court ought to be persuaded by an agency’s interpretation [the view of the conservative justices] and holding that it should defer to that interpretation under certain conditions.”

Where the Justices differ is on their willingness to disregard stare decisis, the doctrine that prior precedent should not be easily overturned. In two decisions earlier this term, justices have noted concern that a majority of the court appeared willing to ignore stare decisis in many areas. However, in Kisor, the four liberal judges, joined by Chief Justice Roberts, did not see a need to entirely eliminate the principle of Auer deference. Only four of the conservative justices would have preferred that seventy years of decisions disappear. That may be the most important result of this case.

The language in the Roberts concurrence distinguishing between agency interpretation of their own regulations and agency interpretation of statutes enacted by Congress may suggest a 5-4 ruling in the future on Chevron deference. The hesitancy of the Chief Justice to disregard stare decisis in even this situation may also suggest 5-4 decisions on other issues before the Court this term or next, where conservatives have attempted for decades to reverse well-established law. However, the loss of another seat to the conservatives would likely bring all of those precedents crashing down.