Sousa won the riding of Mississauga South in the 2007 provincial election, defeating incumbent Tim Peterson. Formerly a Liberal, Peterson had crossed the floor in March 2007 to join the Progressive Conservative Party of Ontario (PC Party).
Sousa emerged victorious in the riding of Mississauga South during the 2007 provincial election, outperforming incumbent Tim Peterson. Formerly a Liberal, Peterson switched parties in March 2007 to join the Progressive Conservative Party of Ontario (PC Party).