The main themes of Bend Sinister by Nabokov are the incompatibility of political freedom and liberty of conscience with forced ideological conformity and coercion by any totalitarian police state, no matter how "good" its professed ideals. Nabokov was concerned with showing how parties with the greatest ideological pretensions to the moral high ground are often the most brutal and repressive in the name of abstract and ultimately unobtainable chimeras like "equality." They use these high-sounding platitudes as the justification for all the terrors of their repressive regimes. Who can object to punishing those who stand in the way of equality, after all?

In Padukgrad, which sounds like a state in the Soviet Union, service to the authoritarian state is promoted as the highest moral good. Individualism is discouraged and repressed. No one is supposed to think of themselves as different from anyone else. A famous philosophy scholar, Adam Krug, is asked to promote the new state ideology of "Ekwilism" by reading a speech to support the "Average Man" party. He says no. His friends warn him to flee the country with his son while he still can, but he naively ignores their warnings. His friends are imprisoned as the state tries to force the famous philosopher to do the dictator's bidding. Krug's son is then kidnapped, and finally, Krug is also imprisoned and eventually murdered (as his son had already been).

Written in the 1940s, when enthusiasm for the Soviet Union was spreading in the United States, Nabakov wanted to warn the American people not to fall for their idealist propaganda of serving the average man. He understood there was little difference between National Socialism (Fascism) and Communism in practice and that the Soviet Union was a brutally repressive dictatorship like Padukgrad. Many naive Americans refused to believe the reports of mass slave labor in the concentration camps of the USSR, the mass executions by the NKVD, and the intentional mass starvation of Ukraine during the collectivization of agriculture, because their rigid ideological attachment to the ideals of socialism blinded them to the ugly truth on the ground.

No ideology that requires complete thought conformity and that must coerce its citizens at gunpoint to support its dictatorship is justified, according to Nabakov. Nabakov preferred the freedoms of a representative republic and couldn't understand why those living in a free republic like the United States could admire any repressive totalitarian police state, no matter what ideals it professed.