YOU’RE a fundamentalist Mormon — that is, the breakaway sect, not recognized by the main church, with a scary compound in Northern Arizona. Women wear long prairie dresses, men rule with an iron fist. You believe in a host of things that violate civil and even criminal law. But your beliefs are “sincerely held.” They come directly from God.

Until Gov. Jan Brewer joined the avalanche of sanity and vetoed Arizona’s so-called religious liberty bill, you may have found some protection in the law. The bill was a green light for bigotry. And indeed, the measure gave those with “sincerely held” religious beliefs the right to refuse service to perceived sinners.

But if you drill down on the logic that all but three of the state’s House Republican legislators tried to enshrine into law, you see a very un-American tenet at work — far beyond the implications for gays and lesbians. You can follow this strain of reasoning up to a pivotal case that will be heard later this month by the Supreme Court.

The Arizona bill, in the eyes of some, was a religious version of the Stand Your Ground law, most recently associated with Florida but used in more than 20 states. You can kill someone, so the Florida statute states, if you “reasonably believe” that homicide is necessary to prevent great harm to yourself. But who says what’s reasonable? Or, in the case of Arizona, how do you judge the sincerity of beliefs? Gumby is less squishy than those standards.