He was a Country Party representative of the electoral district of Lowan (called Borung from 1945 to 1955) from 1944 until his death in 1964.
Mibus studied for the Lutheran ministry at Concordia College in Adelaide, South Australia.
He also attempted three years of a medical degree at the University of Melbourne, but gave up his studies due to severe asthma.
[1] Mibus worked as a campaign manager for his friend, Hamilton Lamb, who was the Member for Lowan from 1935 until 1943.
Lamb died as a prisoner of war in a Japanese internment camp on the Burma Railway, and in his will, recommended that Mibus replace him in Lowan.