On March 27, 2019, the Supreme Court of the United States heard oral argument in Kisor v. Wilkie (No. 18-15), focusing on whether Auer deference should be overruled. While the dispute is not environmental in nature, this case has nonetheless attracted significant attention from the environmental community due to the potentially significant implications to environmental litigation. Auer deference (or Seminole Rock deference) requires courts to defer to an agency’s reasonable interpretation of its own ambiguous regulations. Enforcement actions, permitting processes, and other agency actions are all impacted by the deference agencies receive as a result of the Auer deference doctrine.

The composition of the Supreme Court has also increased attention on Kisor, particularly with the appointments of Justices Gorsuch and Kavanaugh. Justices Alito and Thomas also criticized Auer deference in a 2015 Supreme Court holding. Despite this, oral argument today indicated some hesitancy by the Supreme Court to overturn Auer deference. Questions posed by the Court ranged from how to reconcile the expertise of the agencies versus the courts’ lack thereof, to how tumultuous overturning Auer deference could be to the lower courts. The Supreme Court also focused on the proposed modified deferential standard suggested by the government, which sought to clarify the applicability of Auer deference through the application of six factors. This suggested six factor approach was met with skepticism over whether it would truly result in clarification.

In short, today’s oral argument indicates that the Supreme Court may not be as quick to overturn deference as anticipated.