  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.
