Simplify the following text for a Grade 9 native English-speaking person.
Original: John Mansfield Brumby , MLA ( born 21 April 1953 ) , is an Australian Labor Party politician who was Premier of Victoria from 2007 to 2010 . He became Premier after the resignation of Steve Bracks .
Simplified: Bracks resigned as Premier in July 2007 , and the Labor Party elected Brumby as their new leader .