Christian ISIS. Anyone who hasn't read/watched The Handmaid's Tale has no idea of what this would actually look like. And, just like THT, there will be different rules for those at the top, than for those at the bottom.
Another way that Christian’s Nationalist are similar to Islamist terror groups: they preach a false interpretation of established religious doctrine. I doubt a major of these so called “Christians” practice half the shit listed in whatever version of the Bible they might cite or even read it.