Mexico's main opposition party has swept to victory in a crucial state election, strengthening its bid to retake the presidency and handing a major defeat to the governing conservatives.<br /><br />Initial results on Sunday suggested that the PRI also strengthened its grip on two other states, brightening the political prospects for its PRI's main presidential hopeful, Enrique Pena Nieto.<br /><br />Al Jazeera's Franc Contreras reports from Tolucan.
