Simplify the following text for a Grade 11 native English-speaking person.
Original: Malcolm Bligh Turnbull ( born 24 October 1954 ) is an Australian politician , the former Leader of the Opposition in the Australian Parliament , and former leader of the Liberal Party , succeeding Brendan Nelson on 16 September 2008 .
Simplified: Malcolm Bligh Turnbull ( born 24 October 1954 ) is an Australian politician . He has been a member of the Australian House of Representatives since 2004 , and was Leader of the Opposition and parliamentary leader of the Liberal Party from 16 September 2008 to 1 December 2009 .