He became a member of the Communist Party of Yugoslavia in 1930, and in 1935 was sent to the Soviet Union where he studied at the International Lenin School, Moscow.

He returned to Yugoslavia in 1937 and became a member of the Central committee of the newly found Communist party of Slovenia.

Maček was appointed the rank of general-major and became a member of the Liberation Front of the Slovene Nation in 1944.

After the war, Maček moved into a mansion that had been confiscated from the pharmacist Leo Bahovec.

[2][3] Maček was minister of the interior and vice-president of the Slovene government (1945–1953), vice-president of the Executive council of PR Slovenia and a member of the Federal Executive Council (1953–1963) and also the President of the People's Assembly of SR Slovenia (1963–1967).