I discuss It Can't Happen Here a bit more here. As noted, I enjoyed the book overall, the story speeding along some after the halfway point (by coincidence or not, about after it stopped opening up chapters with brief quotes from the President's campaign book), and would recommend people to take a look. My criticism would be that it was not really a full look at what something like that would look like.
It would probably take longer and be a bit less complete (yes, dramatic license and all that), and it would be interesting to read an account more like that. In effect, one might say the book is a warning of how things would be if it went all the way, thus even 10% is a problem. Or, my citation to "little acts of fascism" (some cry we have a fascist state now ... we don't, but they act like fascists sometimes ... and the "wmou" reply sounds so much like "Karl," who denounced FDR as much as the dictator who replaced him, the word "perspective" not in his vocabulary). There is a point there, but again, both dramatically and as a lesson, a bit of nuance is useful.
And, there are many authors -- Latin American sorts like Isabel Allende come to mind -- who basically go that route fairly well. Still, as the introduction notes, the book was written quickly, and thus put together in a somewhat slipshod fashion ... it was so noted at the time. (The intro usefully notes as well that the author's second wife had gone to Germany, and saw fascism firsthand.) As to introductions and such, there are many editions of Lady Chatterley's Lover (as one might recall, I listened the book recently), each with different introductory/appendicary (a word?) materials. For instance, one has a district court opinion [by Judge Frederick van Pelt Bryan] declaring it not obscene per a federal mail statute.
And, another edition has Lawrence's own introduction to one printing, which dwells on his views on sexuality and such. I need to read the whole thing, but the district noted [citing an opinion of Frankfurter] Lawrence's judging porn and erotica differently. It has long amused me that somehow protection of material should rely on the good intent of the publisher (a "leer" vs. an upright promotion of serious thought) or on the good taste of the material (Playboy vs. a less glossy imitation).
It is on some level silly to spend lots of time defending the worth of the likes of late night soft core porn, but seriously, such material promotes ideas as worthy of protection as many similarly trite/cheaply made/silly non-sexual materials. If there was some "serious and good intentioned" test for free expression, I dare say many would fail. Anyway, I know a woman who wrote a college term paper analyzing skin magazines ... her husband not really gung ho to go around with her to collect the "literature" involved.
Sadly, I never thought of asking her to let me view the final result.