I read _It Can't Happen Here_ in high school, about 50 years ago. It made a strong impression on me, and quite a few bits of it have stuck in my mind: lab glassware piled outside a classroom with soldiers drilling inside; dissidents being whipped with steel fishing rods. In my recollection it was obviously meant to be a satire, not a novel with real people in it. Surely his calling the U.S. dictator Berzelius (Buzz) Windrip is evidence enough of that!

The book appeared in 1935. The satire must have been partly aimed at Huey Long.