It's not a swing _back_: it's just a different axis altogether. Being narcissistic enough to insist that your ideological opponents are evil and that every forum is an excuse to root out wrongthink is an ancient tendency. It's pretty ideology neutral.

Fifty years ago people were doing it for not being a good enough Christian. Now it's for not buying into every detail of an incredibly specific (and quite flawed, imo) political philosophy, or even just claiming that perhaps it's counter productive to fight every battle simultaneously in every forum.