John Walker began his career in labor at a young age, joining the Knights of Labor and later becoming a full-time organizer for the United Mine Workers of America. He served multiple terms as president of District 12 and founded the Illinois State Cooperative Society. Walker transitioned from the Socialist Party to the Farmer–Labor Party, eventually becoming its national chairman. He held various leadership positions within labor unions and engaged in significant contract negotiations, including one in 1932 that resulted in substantial pay cuts for coal miners.

John Walker's political identity is marked by a blend of ideological loyalty and strategic pragmatism, navigating between labor advocacy and pragmatic economic negotiations. His unexpected support for significant pay cuts for coal miners in 1932, despite his strong advocacy for labor rights, reveals a calculated approach to protecting regional industrial interests. Walker's shifting affiliations, from the Socialist Party to the Farmer–Labor Party, highlight a willingness to adapt his ideological positioning to align with broader political movements.