How did the idea of the "Soviet Union" (a union of councils) mutated/evolved into a “people's republic” (a certain ethnofederalism) with the ethnicities as the main building blocks?
For instace, a multi-ethnic Soviet republic like the Bukharan People's Soviet Republic dissolved into several ethnic people's republics.
Has the idea of an ethnicity-centered people's republics emerged at some point in the history of the Western-European Left, or is it observered only in the East Bloc?
Why the idea of the people's republics became the main form of the communist/socialist states in the East Bloc and the Third World?