August Bebel
From 1899 to 1906, Müller worked as an editor at the Socialist newspaper "Görlitzer Volkswacht". He was member of the local parliament ("Stadtverordneter", 1903 to 1906) and a party functionary ("Unterbezirksvorsitzender"). August Bebel nominated him in 1905 (without success) and 1906 (successfully) for membership of the board of the national SPD.