Liberal Party

Elected in 1993 to the seat of Mawson with the Dean Brown Liberal Party government, he was re-elected in 1997 and 2002.

In 1998, Brokenshire was promoted to cabinet in the John Olsen government. His roles included Minister for Police, Correctional Services & Emergency Services, Minister for Gambling, Minister for Volunteers, and in opposition, Shadow Minister for Health. Brokenshire served three parliamentary terms representing the Liberal Party.

After losing the seat to Labor at the 2006 election, he was denied Liberal Party pre-selection for Mawson for the next election.

Family First Party

Brokenshire contested the seat of Kingston for the Family First Party in the 2007 federal election, receiving 5.71 percent of the vote.^[3][4] On 18 March 2008, he was chosen by Family First to replace Andrew Evans, who had retired from the Legislative Council,^[5] and Brockenshire was sworn in on 24 July 2008.^[6][7] A few years later, he expressed interest in switching to a Lower House seat,^[8] but never did so.

Brokenshire has employed the Freedom of Information legislation as part of his political strategy.^[8]

Brokenshire sat on various parliamentary committees, including the Public Works Committee, Select Committee on the Emergency Services Levy, Families SA Committee, Aboriginal Lands Parliamentary Standing Committee, Budget and Finance Committee, Certain Matters Relating to Horse Racing in South Australia, and Natural Resources Committee. He opposed the abolition of the Legislative Council.^[9]

Australian Conservatives

In 2017, Brokenshire and Dennis Hood joined the Australian Conservatives when Family First ceased to exist.^[10] He failed in his bid to be re-elected to the Legislative Council at the 2018 South Australian election.^[11]