Any discussion of the politics of It Can’t Happen Here should keep in mind that Sinclair Lewis, the author, whas a political moderate although he had been around the left wing for a while in his youth. In his novel, Lewis satirized the conservative midwestern small town life ha had grown up in, but he also satirized the left wing. 

Doremus Jessup, the hero of It Can’t Happen Here is a moderate Republican editor whose motto is: "Blessed are those who don’t think they have to go out and Do Something About It!" 

But then Doremus Jessup, like his creator Sinclair Lewis is plunged into the chaos of the Depression, when American society seemed to be falling apart. 

When Americans looked for solutions to the Depression, the great majority went no further than the liberal reforms of President Franklin Roosevelt’s New Deal. But for many, these reforms did not seem to be effective and they looked for something more drastic. 

Lewis believed that most of those who wanted more radical solutions would not turn to the small American left wing, but to the right. He based the two villains of It Can’t Happen Here, Buzz Windrip and Bishop Prang on the two leading right-wing demagogues of the Thirties, Huey Long and Father Coughlin. 

Doremus Jessup for all his moderation and trying to get along with the new right-wing dictatorship, winds up in a concentration camp. When he escapes from the concentration camp, he finds himself part of the resistance movement because that is all there is left for him to do. He blames himself for the failed revolution because he did not take Buzz Windrip more seriously when there was still a chance to stop him. 

It Can’t Happen Here is not a revolutionary book. It reflects the fears of essentially moderate people like Sinclair Lewis that that desperate conditions of the thirties would sooner or later leave them no other choice than revolution.