Of course it's all of them. But just like in any cult, the primary culpability for fascism lies with the cult leader (which is Trump in this case). It's similarly to the allocation of blame in the case of Hitler with Nazi Germany, Stalin with the Soviet Union, Pol Pot with Cambodia, etc. Even though many share the guilt and burden of culpability, the metaphorical 'head of the snake' is often the 'chief enabler' of such movements and events.