Comment: It’s been my opinion that the alt-right basically started gaining traction as a thing as the progressive Social Justice Warriors began seeking to expand their influence into new areas, such as science fiction (see: the circumstances leading up to Sad/Rabid Puppies), video games (see: Gamergate), open-source software development (see: this post by Our Host), and even heavy-metal music (see: this description of “Metalgate”). Clearly, they’d like to see their brand of political correctness spread everywhere.
“Always leave your opponent a line of retreat–unless you want a fight to the death.” The SJWs don’t want to leave any lines of retreat. Consequently, it seems inevitable that a group of people, drawing from some of the same groups reacting to the above developments, would decide to band together and proclaim, “If it’s war they want, then war they shall have!”