Moral Relativism and Moral Fanaticism

What exactly is moral fanaticism?  Like moral relativism, moral fanaticism is a meta-ethical theory – a theory about moral facts and moral reasoning.  Moral relativism says, roughly, that there are no moral facts, and moral “reasoning” is just thinly-veiled emoting.  Moral fanaticism, in contrast, affirms that there are moral facts, but pretends that thinly-veiled emoting is ironclad moral reasoning.