I think I am coming up with a one-sentence definition of fascism.

Over the last three years, I've had to put a lot of study into the nature of just what fascism is. I've had to conclude that it is quite distinct from authoritarianism, though naturally they overlap frequently. What exactly qualifies someone, or some movement, as fascist? I think the essence of it is the division of the populace into "right people" and "wrong people". Here is my definition:

Fascism is the advocacy of privileging one cultural group above other cultural groups within a populace, both through the power of the state and through extralegal means.

Any group that uses "blood and soil" arguments -- that is, saying that a given area of land rightfully belongs to one ethnic group and other groups should have lesser rights there -- qualifies as fascist, if the movement is willing to use forceful coercion to obtain such an end. It does not matter if they are otherwise not authoritarian.

Willingness to use threats and violence is part of the requirement. If a group claims that they have special rights to something but is willing to use only nonviolent protests, they aren't fascist.

Communist regimes -- no matter how totalitarian -- generally do not qualify as fascist, because communism lumps all of the people into a single cultural group to suffer equally.

Democratically elected regimes do qualify as fascist if they allow some kinds of people the right to vote but not others.

Nationalism is closely related to fascism, but a distinction can be drawn.