Career
He was sworn in as Minister for Aboriginal and Torres Strait Islander and Multicultural Affairs and Minister assisting the Premier on 3 April 2012. On 16 April 2012 Dempsey was appointed acting Minister for Police and Community Safety following the resignation of David Gibson due to driving with a disqualified licence. He was appointed to the office in his own right on 23 April 2012, and Glen Elmes replaced him as Minister for Aboriginal and Torres Strait Islander Affairs and Minister Assisting the Premier.
Dempsey was appointed the Shadow Minister for the Environment and the Shadow Minister for Sport and Recreation in November 2010.
He was appointed as Shadow Minister for Mining and Resource Management in 2011.