He became a socialist while teaching at the Protestant University of Marburg and became active in the Social Democratic Party of Germany for whom he was an unsuccessful candidate in the 1903 German federal election.

[8] He achieved international recognition for his historical and sociological study, Zur Soziologie des Parteiwesens in der modernen Demokratie.

Untersuchungen über die oligarchischen Tendenzen des Gruppenlebens, which was published in 1911;[9] its title in English is Political Parties: A Sociological Study of the Oligarchical Tendencies of Modern Democracy.

Because Michels admired Italian culture and was prominent in the social sciences, he was brought to the attention of Luigi Einaudi and Achille Loria.

They succeeded in procuring for Michels a professorship at the University of Turin in 1907,[12] where he taught economics, political science and socioeconomics until 1914.