So your supposition is that he was just writing a normal paper about biology for the general public and then he just sort of accidentally added an aside about p

So your supposition is that he was just writing a normal paper about biology for the general public and then he just sort of accidentally added an aside about politics at the end that reframes the whole piece and is extremely relevant to the controversy about democracy vs. dictatorship in the 1920s? No. It's a single extended essay that advances the thesis that human social structures should "be the right size." His other work work is the equivalent of Origin of Species for him, but this is one very short essay with a coherent thesis.