georgia10 on DailyKos at the link above does us the courtesy of reprinting Article VI of the Constitution:
Q: A recent poll found that 55 percent of Americans believe the U.S. Constitution establishes a Christian nation. What do you think?
A: I would probably have to say yes, that the Constitution established the United States of America as a Christian nation. But I say that in the broadest sense. The lady that holds her lamp beside the golden door doesn't say, "I only welcome Christians." We welcome the poor, the tired, the huddled masses. But when they come here they know that they are in a nation founded on Christian principles.
The Senators and Representatives before mentioned, and the members of the several state legislatures, and all executive and judicial officers, both of the United States and of the several states, shall be bound by oath or affirmation, to support this Constitution; but no religious test shall ever be required as a qualification to any office or public trust under the United States.as well as the First Amendment of the Constitution:
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the government for a redress of grievances.