Complex sentence: Heenan ran in the subsequent by-election, this time as a Liberal and was elected and joined Mitchell Hepburn's Cabinet serving as Minister of Mines and Forests (1934-1941) and Minister of Labour (1941-1943).
Split into simpler sentences: Heenan ran in the subsequent by-election, this time as a Liberal Party candidate, and was elected. He joined Mitchell Hepburn's Cabinet and served as Minister of Mines and Forests (1934-1941) and Minister of Labour (1941-1943).