Constitutional Precedent of Amicus Briefs

Abstract: We investigate shared language between U.S. Supreme Court majority opinions and interest groups' corresponding amicus briefs. Specifically, we evaluate whether language that originated in an amicus brief acquired legal precedent status by being cited in the Court's opinion. Using plagiarism detection software, automated querying of a large legal database, and manual analysis, we establish seven instances where interest group amici were able to formulate constitutional case law, setting binding legal precedent. We discuss several such instances for their implications in the Supreme Court's creation of case law.