Fascism cannot flourish, in any of its shades, without sewing hatred between citizens along race, gender, class and ethnic lines.  Authoritarianism works by creating a violently US vs. THEM society where loyal citizens know who to lash out at.   

Unions of organized labor, while sometimes problematic (union officials often become middle-men, protecting their own turf and working with the bosses) are also inherently democratic.  If you do the job, and want fair pay, and better working conditions, you forget the “differences” you may have with your co-workers and band together for common interests.  Often you become friends in the process.

Dictators and oligarchs HATE this kind of thing.