The endorsement test was proposed by Sandra Day O'Connor , a member of the United States Supreme Court . She proposed it in her judgment in a lawsuit called Lynch v. Donnelly in 1984 . The endorsement test proposed by United States Supreme Court Justice Sandra Day O'Connor in the 1984 case of Lynch v. Donnelly asks whether a particular government action amounts to an endorsement of religion , thus violating the Establishment Clause of the First Amendment .