Fascism is a social disease that is injected by the bourgeoisie into the petit-bourgeoisie during times when capitalism is in crisis. They do this through propaganda and economic warfare like austerity coupled with tax cuts for the rich. This results in an economic downturn that hits the “middle class” the hardest (relatively - poor people are also fucked, but they had less to lose in the first place). Economic woes coupled with divisive and authoritarian propaganda and — boom — fascism.

So how do you stop it? Well, ultimately by dismantling capitalism and removing the power of the bourgeoisie. Otherwise fascist crises will just keep being manufactured.