No worries. It’s a short read as far as essays go. Both the Nazi and Fascist parties were authorization but neither were left or right in the modern US instances. Eco’s whole point was to divest the cultural and time trappings of this brand of authoritarianism into a general definition of modern populist authoritarianism. It’s a good read.
First time I saw this, it had a title something like: Watch the monkey not get the reward!