The once-obscure "major questions doctrine" (MQD) has become one of the most controversial rules of legal interpretation applied by federal courts. Over the last two years, the Supreme Court has used it in several major cases, including the eviction moratorium decision, the OSHA large-employer vaccine mandate case, West Virginia v. EPA, and—most recently—Biden v. Missouri, the ruling striking down President Biden's plan to forgive $430 billion in student loan debt. The doctrine requires Congress to "speak clearly when authorizing an [executive branch] agency to exercise powers of vast 'economic and political significance.'" If such a broad delegation of power isn't clear, courts must rule against the executive's claims that it has the authority in question.
