On November 6, 2013, the US Supreme Court heard [PDF] arguments on the constitutionality of legislative prayer. The US Court of Appeals for the Second Circuit ruled in Town of Greece v. Galloway that an opening prayer in a town meeting amounted to the government endorsing Christianity. Therefore, the town's practice was in violation of the Establishment Clause. The Supreme Court's jurisprudence on the subject ranges from school prayers to nativity scenes.
In Lee v. Weisman, ruled that opening and closing prayers at a high school graduation ceremony were incongruous with the Establishment Clause. The First Amendment's Free Exercise Clause, which protects the freedom to practice the religion of one's choice, was not protective of the practice. Justice Sandra Day O'Connor opined that government accommodation of religious practice was only permissible when it removed bars to free exercise. The permissibility of prayer at graduation did not disbar free exercise of religion and its omission did not impose a burden on religious free exercise.
Justice O'Connor's opinion reflected the court's 1947 decision in Everson v. Board of Education of the Township of Ewing, where it ruled, ruled a state statute that reimbursed school bus taxes to parents of children bussed to parochial schools was constitutional pursuant to the Free Exercise Clause. This clause directly follows the Establishment Clause and analysis of one often prescribes harmony between the two.The statute was held to be a protection from obstacles to religious practice, not a state aid of religion. Reimbursement was necessary in order for the state government's compliance of the Establishment Clause because it prevented a disadvantage to religious exercise. This marked the first time the Establishment Clause was held as binding on the states through the Fourteenth Amendment's Due Process Clause.
The court took a different stance on parochial reimbursement in it's 1971 decision in Lemon v. Kurtzman. Reimbursement for the secular dimensions of the parochial schools went against the Establishment Clause. The ruling introduced the Lemon Test, which requires the government to legislate only secularly, neither help nor hamper religious practice and not become infused in religious matters. The court deemed Catholic schools to be too large a part of the church's functions for the government to be involved. Government financial assistance of religious practice was first reviewed by the court in Bradfield v. Roberts in 1899. A Roman Catholic hospital was allowed financial assistance from the government because the funding was for a secular activity. The Court ruled religious affiliation does not preclude government funding so long as the monies are allocated to secular services.
The Lemon Test was applied in the 1989 case of County of Allegheny v. American Civil Liberties Union. The court decided that a nativity scene and menorah set outside government buildings violated the Establishment Clause by promoting religion. This contradicted the 1984 case Lynch v. Donnelly, the court held that a nativity scene in a park in conjunction with a "seasons greetings" banner and Santa Claus figure did not violate the Clause because no specific religion was promoted.
In 2005, the court heard two cases involving placement of the Ten Commandments outside of government buildings. In Van Orden v. Perry, the court ruled [PDF] the placement to be legal because there were other symbols on the stone medium and for their inherent historical value. The Ten Commandments in McCreary County v. American Civil Liberty Union [PDF] were deemed illegal because they were purely religious in nature. In both cases, the defendants wanted the court to do away with the Lemon Test, but the tool of review withstood.