Complex sentence: McMahon made his first bid for the prime ministership in 1968, following Holt's disappearance; his candidacy was vetoed by John McEwen, the leader of the junior party in the governing coalition.
Split into simpler sentences: McMahon made his first bid for the prime ministership in 1968, following Holt's disappearance. His candidacy was vetoed by John McEwen, the leader of the junior party in the governing coalition.