There's a scifi story that pops up a few places. I remember it in Babylon 5, and it sort of figures into basic Dalek mythology. But, anyway, there's a species or creature or robot or whatever that's designed kill everything that isn't genetically pure enough, anything that isn't part of the correct race. Inevitably it goes wrong, and decides nothing or no one is pure enough and starts slaughtering everybody. I kind of see conservative bloodlust this way. They really do
want the deaths of "the other," the only question is precisely how they define that, how large their recognized tribe is.
