 He bought and operated a pharmacy in Margaret Street, and was elected as a City of Toowoomba alderman in 1976.In 1976, Gordon Chalk, the state Liberal leader since 1965, retired from politics mid-term, causing a by-election in his seat of Lockyer.Bourke was selected as the Liberal candidate to succeed him, but faced a strong challenge from National Party candidate Neville Adermann, son of former federal minister Charles Adermann.