It was originally shortened in German from ”Antifaschistische Aktion” and ”Außerparlamentarische Opposition”. Then that carried over to other languages as a common name. Feel free to go back to the roots! ;)

disregarding the history of the term, you see that even posters on Hacker News Dot Com dispute the accuracy of the term "fascism" as applied to contemporary american politics, so what difference would it make? people who are okay with fascistic politics will not distinguish opposition with a name change.