Democracy has nothing to do with it when the democratically elected morons breach people's constitutional rights. If you democratically elected a bunch of people who decided to institute Islam as the official religion of the United States, you'd be one of the first of the mouth-breathers lining up in protest.
"The real object of the [first] amendment was, not to countenance, much less to advance Mahometanism, or Judaism, or infidelity, by prostrating Christianity; but to exclude all rivalry among Christian sects, and to prevent any national ecclesiastical establishment, which should give to an hierarchy the exclusive patronage of the national government..." - Supreme Court Justice Joseph Story