This was a group of secular people who drifted toward far right ideation, embracing multiple forms of bigotry, and eventually, politically violent ideologies because their sense of cultural "rightness" was threatened by groups of people who frightened and enraged them.
A bunch of frightened, angry secular/atheist white people, who felt threatened by the world's cultural shifts, eventually banded together with the political forces of white religious fascism to form the mess we see today.