> On a more concrete note, didn't I hear once that the "separation of church and state" idea wasn't actually a part of the Constitution, or something else along the lines of it not actually being formally guaranteed?

It's guaranteed by our First Amendment: "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof."

The phrase "separation of church and state" comes from, I believe, a letter written by Thomas Jefferson, who said the First Amendment was like a wall, creating a separation of church state. It has pretty much always been intrepreted as meaning that the federal government[1] cannot establish a state religion.

Its actual application has been mixed, and even the Founding Fathers were a bit confused about how to interpret it. James Madison, for instance, voted to approve a paid Congressional chaplain while he was a member of the Congress. Later in his life he wrote that action was probably unconstitutional under the First Amendment. And this is the man who helped write much of the Constitution and Bill of Rights.

Over the last few decades, the Supreme Court has ruled that the "Establishment Clause" prohibits government actions that would, as their principal or primary effect, either advance or inhibit religion, as well as laws that would cause "an excessive government entanglement with religion." Some rulings have gone so far as to say any government actions that endorse religion are unconstitutional.

Ste "Constitutional scholar lately" phen

[1] And, like most of the Bill of Rights, the Supreme Court applied the First Amendment's Establishment Clause restriction on governments to the state governments in the Twentieth Century, assuming it was covered under the Fourteenth Amendment's "equal protection" clause.