Dean was elected to the House of Representatives at the
1977 federal election as the Liberal member for the marginal seat of
Herbert. He was re-elected in 1980, but fearing electoral defeat, backed a failed effort in 1982 to oust
Prime Minister Malcolm Fraser and replace him with rival
Andrew Peacock. He was nonetheless defeated at the
1983 federal election by the Labor candidate
Ted Lindsay.
Later career Dean returned to legal practice after his 1983 defeat, becoming a partner in the Townsville firm of Nehmer Davenport Dean. He moved to
Brisbane for family reasons in 1987, working as an associate for James Byrne & Associates and then Ray Rinaudo. He also returned to broadcasting as a presenter on community radio station
4MBS. Dean was appointed to the
Magistrates Court of Queensland on 23 June 1997 and retired on 12 June 2007 when he reached the mandatory retirement age of 65, having served mostly in
Brisbane with a stint in
Warwick between 1999 and 2002. He continued as a magistrate until 2007. ==Death==