In the early days of the union, America's founding fathers made a few additions to their fledgling constitution. The first of their amendments ensured religious liberty. And to make sure no religious group could subjugate any other, public life would be strictly secular.
Today, even with the Christian Right a vociferous force in political debate, the separation of church and state endures. And while anyone can establish their own private school, and preach whatever they choose, in America's public schools religion stops at the gate.
Despite rock-solid protection in the US constitution, a Missouri politician felt the right to worship could do with a little local booster. For six years, Republican Mike McGhee, a member of Missouri's House of Representatives, has called on his state to adopt its own constitutional amendment. Last month Mr McGhee, whose supporters include the Baptist and Catholic lobbies, finally got his wish. In a state-wide referendum, 83 per cent voted in favour of his proposal.
The change, as it was put to the people, sounded innocuous enough. Who could object to the three headline points spelled out on the ballot paper: the right of citizens to express their religious beliefs; the right of a child to pray, voluntarily, at school; and the requirement that public schools display the Bill of Rights?
The complete amendment, however, is more contentious. Had all those 83 per cent read the text in full, some may have had pause. One line in particular might have raised alarm: "that no student shall be compelled to perform or participate in academic assignments or educational presentations that violate his or her religious beliefs." Schoolchildren in Missouri now have the power to opt out of parts of the curriculum; religion has crept into the classroom.
What will this mean in practice? In a state with some of the weakest gay rights law in the country, social studies classes that tackle homosexuality could be shunned as offensive. Indeed, Mr McGhee cited the 2006 case of Emily Brooker, a college student instructed to lobby the Missouri legislature to grant adoption rights for gay couples as part of her course. She claimed that she was penalised after refusing on religious grounds.
Science education could also inspire rebellion - 46 per cent of Americans are Creationists, believing God created humans in their present form. Glenn Branch of the National Center for Science Education, an opponent of the amendment, believes that Missouri could become a testing ground for efforts by the religious right to roll back the teaching of evolution.
And how about Classics, PE or long division? Who, as Mr Branch asked, will sort the legitimate objections from the frivolous? Would a child invoking her Wicca beliefs be taken seriously? Or followers of the increasingly popular Star Wars religion Knights of the Jedi?
If it comes to that, the courts will likely decide. And the state will be put in the unprecedented position of judging the validity of particular religions. Certainly not what the founding fathers had in mind.