The religion clauses of the First Amendment provide that Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof… In modern times the Supreme Court has frequently construes these clauses to create, in Thomas Jefferson’s oft-quoted metaphor, a wall of separation between church and state . The Court’s decisions have precipitated substantial opposition and, in particularly since the election of Ronald Reagan to the Presidency in 1980, a concerted and partly successful effort to change its separatist constructions of the religion clauses. This volume summarises the doctrinal debates and shifts on the religion clauses that have occurred on the Court during this period. It summarises and examines as well the legal effect of each of the 56 decisions the Court has handed down concerning church and state since 1980.