He was a Liberal Party member of the Victorian Legislative Assembly from 1988 to 2018, representing the electorates of Balwyn (1988–1992) and Box Hill (1992–2018).

Clark's instrumental role in these actions resulted in significant changes to the law relating to student unionism in Victoria.

After working as a solicitor practicing in commercial, financial and labour law from 1983 to 1988,[4][5] Clark was elected to the Victorian Legislative Assembly seat of Balwyn on 1 October 1988.

[1] Following the division of electorate boundaries in 1991, Clark successfully sought re-election in the seat of Box Hill and subsequently assumed the role of Parliamentary Secretary to the Victorian Treasurer, Alan Stockdale, in 1992.

Following the 1996 Victorian state election, Clark was appointed as Parliamentary Secretary, Treasury and Multimedia, a position he held until the Coalition lost Government in October 1999.

After the defeat of the Coalition at the 2014 state election, Clark unsuccessfully contested the deputy leadership of the Liberal Party.