The attitude of the government of the United States toward religion is defined by the Establishment and Free Exercise clauses of the First Amendment of the United States Constitution. It stipulates "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof." This has resulted in much discontent and emotional defense of the clause. There has also been extensive analysis based on a flurry of cases brought before the United States court system to determine the constitutional legality of a number of issues relating to the regulating or celebrating of religion in the public sphere. This included, for example, issues of prayer in public schools and the display of holiday decorations in government buildings. Several contemporary movements exist that try to further strip religion of any attachment to government or its representatives, or on the contrary attempt to negate the Establishment Clause in favor of more Christian policies in the United States.
Answering unsatisfied Baptist constituents in Massachusetts, Thomas Jefferson once defended the Constitution by outlining its perceived intent, to put a "wall of separation between church and state." The quote is one of the oldest uses and simultaneously most prominent expressions of the common phrase and it has been quoted in at least two Supreme Court decisions.
On the issue of the institution of prayer in public schools, the Supreme Court in the 1960s repeatedly criticized and ruled illegal the compelling, by any faculty, to recite any composed prayer. Additionally, the reciting of the Lord's Prayer and recitation from the Bible was ruled out of bounds. In 1985, the court met with a quagmire when the Alabama state legislature passed a law mandating moments of silence in school which could be used for the purpose of prayer. The court ruled the law unconstitutional for attempting to advance religion, though the allowing of moments of silence, without stipulating religious usage of the time, was implied to be within the bounds of the constitution.
The discussion of Christianity in America is often brought up in the context of the so-called "Culture Wars," where an apparent divide between regions of the country on major national issues splits along secular-liberal and religious-conservative lines. Issues often identified as constituting the battlegrounds of the war are abortion, same-sex marriage, prayer in public schools, religious displays at public and government places, and the separation of church and state. The issue of separation is seen as a fundamental element of the fight and as an exemplification of the conservative viewpoint. This can be seen in a critique by M. Stanton Evans stating that Americans conventionally accept what he calls the "absolutist doctrine" of Supreme Court Justice Hugo Black in his 1947 decision. In that ruling he stated that the First Amendment can only be interpreted in a way that accepts, among other things, the notion that the state cannot sponsor institutions which promulgate distinctly religious principles or values.
Critics of the Christian right have alleged that religious leaders are fomenting a view of American history and its constitution that re-frames the United States as a country founded in order to serve Christian purposes. One view popular among scholars which has been utilized in the political outlook of many right-wing Christian thinkers is that the founding fathers of the United States directed their constitution against the Church of England, but still showed favor toward religiously influenced policies. Politicians and community leaders have been criticized for using this idea to insinuate that Christian values were intended, if not implied, by the actions of these figures in history. This view, too, has been criticized as slanted and a subjective use of historical sources.
The debate is usually generalized by many conservative Protestant leaders as a fight that could relate to Orthodox Jews and traditional Catholics. However, sometimes talk can border on tension between communities, such as conservative Pat Buchanan's denunciation of the controversy over the Mel Gibson film, "The Passion of the Christ," which had enraged leaders throughout the American Jewish community.
The United States also maintains an active liberal stream of religious groups mostly in the Jewish and Christian communities. Various mainline Protestant groups and others such as the Union of Reform Judaism have openly advocated positions on political issues diametrically opposed to those on the Christian Right or of Orthodox Jews. The Union of Reform Judaism also maintains a political action office in Washington D.C. called the Religious Action Center.
Religious groups have contributed to debates via lobbying on matters of foreign policy particularly on issues like the Israeli-Palestinian conflict. Right-wing Christian groups, mostly Evangelicals but increasingly also traditional black Churches, have sent student and clergy delegates to conventions run by AIPAC, the America Israel Public Affairs Committee. The Israeli ambassador to the United States in 2011, Michael Oren, has argued that American Christians have long supported the notion of a Jewish state and their support is a demonstration of an American cultural heritage that is makes them an independent partner of pro-Israel political lobbying in the United States.