Career
He resigned from the Liberals and was elected to the safe Liberal seat of MacKillop in the state"s south east at the 1997 election as an independent, but re-joined the Liberals in 1999. He has been re-elected in MacKillop as a Liberal since the 2002 election. Williams took advantage of a public backlash against Mr Baker who was accused of impropriety over a forestry land deal.
Williams rejoined the Liberal Party in December 1999.
He was re-elected in MacKillop at subsequent elections. Williams was elected unopposed as Deputy Leader of the Liberal Party in South Australia on 6 April 2010.
On 19 October 2012, Martin Hamilton-Smith announced he would be challenging Isobel Redmond for the parliamentary leadership of the South Australian Liberal Party, with Steven Marshall challenging Williams for the deputy leadership.