In Lemon v. Kurtzman (1971), the Supreme Court ruled that
polygamy, as once practiced by the Mormon Church, was unconstitutional since religious practices cannot make an act legal that would otherwise be illegal.
free speech can be limited by the government when the speech presents a "clear and present danger" of bringing about "substantive evils".
government mandated prayer in public schools is unconstitutional as a violation of the First Amendment's establishment clause.
government funding to private religious schools had to be clearly secular, must not advance nor inhibit religion, and must not foster an "excessive entanglement" between government and religion.
the exclusionary rule was to be extended to the states through the process of selective incorporation.