Hate speech is like the hammer on the tool-belt of fascism, and prejudiced people are the nails.
Fascism is a nationalistic system of governance which bundles together particular ideas about religion, race and economics under one nationalistic movement (i.e. National Fascist Party, Nazi Party, Make America Great Again). Fascism ignores the fact that there are many divergent voices and beliefs which can comprise one country, therefore raising fear and anger by "bundling" together a wide array of complex voices into a falsely simplified group which becomes the target of blame, hatred, violence and systematic oppression. Fascism is a rhetorical maneuver, in which scapegoats are "bundled" together. ***Fascism is not a zero sum game: aspects of it can be found in the messages of most mainstream, contemporary politicians from stances on prison policies to racial profiling and processes of state prosecution.
A broad stroke: Bernie Sanders would not have been a fascist - Donald Trump has already shown himself to be one.