[1] Dean Brown's political career was marked by his rivalry with John Olsen, the two representing the moderate and conservative wings of the South Australian Liberal Party respectively.
After Tonkin lost the 1982 election and retired from politics, Brown ran in the ensuing leadership contest, losing to Olsen.
For the 1985 election, an electoral redistribution left both Brown and Stan Evans, the member for Fisher, vying for Liberal preselection in Davenport.
The Labor government of John Bannon was embarrassed by the losses of the State Bank of South Australia, but incumbent Opposition Leader Dale Baker was unable to capitalize.
It initially appeared that Olsen, who had been appointed to the Australian Senate after losing the 1989 state election, would return to his old post with little difficulty.
They persuaded leading party moderate Ted Chapman to stand down from his equally safe seat of Alexandra on the Fleurieu Peninsula and hand it to Brown so he could challenge Olsen for the leadership.
However, he had considerable difficulty reining in his large party room, which was torn by the factional battles that have long plagued the SA Liberals.
Well aware that the Liberals had a year at most to recover before the next election, two prominent moderate backbenchers, Joan Hall and Graham Ingerson, the latter having briefly served as Brown's deputy in Opposition, threw their support to Olsen.