Establishment Clause: government may not establish or support any official religion
Controversy over whether state aid to private religious schools violates Establishment Clause
Many of the most controversial questions involving the establishment clause have surrounded education; more specifically, the Court has repeatedly been asked to decide whether state aid to religious schools violates the establishment clause of the First Amendment. If the government provides any sort of assistance to these schools, is it breaking the wall of separation between church and state and unconstitutionally advancing religion?
The first answer to the question came in 1947 when the Supreme Court was asked to consider whether New Jersey could finance the transportation of Catholic School children on public buses. In Everson v. Board of Education, the Court said yes, it could. Transportation, like fire and police protection, served the public welfare, and certainly, the public fire department had an obligation to respond if the Catholic School caught on fire. Moreover, the primary beneficiary of the bus ride was the child, not the school, which received only a secondary and incidental benefit.
The "child benefit theory" that emerged from this ruling became a critical element in resolving subsequent cases of this type. And it was combined with other questions that the courts had developed to measure the legitimacy of a specific form of public aid. Was the primary purpose of the aid secular in nature? Did it advance or inhibit religion in any way? If the answer to the first question was yes and to the second was no, then the Court generally considered the aid constitutional.