In recent years, the Supreme Court has repeatedly deployed a new doctrine with potentially seismic implications for the future of the federal administrative state. The “major questions doctrine,” formally embraced by a majority of the Court for the first time in West Virginia v. EPA, requires administrative agencies to demonstrate “clear congressional authorization” when they assert authority over matters of “vast ‘economic and political significance.’” But what makes a question “major” or congressional authorization “clear”? And how might this doctrine affect related principles of administrative law?

As the Supreme Court has left these questions unanswered, this Note provides the first account of how lower courts and litigants are attempting to fill in the gaps. It first examines the contexts in which litigants and courts have addressed the doctrine and the strategies that challenger plaintiffs and governmental defendants have employed. It then analyzes how courts and litigants have applied the elements of the major questions test and assesses the implications of that test for two administrative law doctrines with uncertain fates: Chevron deference and nondelegation.

As this Note explores, the major questions doctrine has already featured in challenges across a vast expanse of policy areas, including environmental regulation, public health, education, immigration, data privacy, labor and employment, election law, public safety, and national security, economic affairs, and anti-discrimination law. The doctrine has also been used to challenge various types of executive actions, including agency rules and regulations, enforcement actions for statutory violations, presidential (nonagency) actions, and actions that confer a public benefit rather than regulating private conduct. While the major questions doctrine remains in its early stages of development, this Note identifies emerging trends in an important group of “first movers” to illuminate the doctrine’s potential impact in the years to come.