U.S. Supreme Court Receives Notice That Cato Institute and Pacific Legal Foundation Will Support Petition Challenging Federal Cannabis Prohibition

The notice, submitted by attorney David Boies on November 24, informs Clerk of Court Scott Harris that both groups plan to file briefs amici curiae on or before November 28, the deadline set under the Court’s rules. According to the letter, the respondent waived the right to respond to the petition on November 17. That waiver triggers distribution of the petition on November 25, three days before amicus briefs are due. The letter points out that the Thanksgiving holiday pushes the standard 30-day amicus window to November 28. Boies requests that the Court circulate the letter alongside the petition so the Justices are aware that multiple amici will be filing in support.

The case, No. 25-518, asks the Supreme Court to review issues central to federal marijuana enforcement and state-legal businesses, a dispute that has drawn growing national attention. With two influential libertarian-leaning organizations preparing to weigh in, the petition is positioned to receive additional visibility as the Court decides whether to grant certiorari. The letter notes that additional amici may also submit briefs by the November 28 deadline if the Court does not call for a response.

This procedural update marks the latest development in a case that could shape the legal landscape for state-licensed marijuana companies nationwide. The filing comes just days after the conservative Americans for Prosperity Foundation, founded by Charles Koch, urged the U.S. Supreme Court to rule on the constitutionality of federal marijuana prohibition, arguing Washington cannot criminalize activity that occurs entirely within a state.