It can't happen here

A dystopian tale of a dictatorial US President, who appeals to the voters with his "clownishness" (remind you of anyone?). 

It could be an instruction manual for despots and dictators everywhere, with some of what goes on strikingly similar to both old and recent cases of Our Glorious Leaders stamping out the freedoms of their people with violence. 

It was written in 1935, but still seems very relevant.  It mentions the goings on of Hitler, Mussolini, and other fascist / communist dictatorships.  At a time when the UK was still on speaking terms with them.