Campaigning has ended in Mexico's presidential election which could see the PRI, the party which ruled for most of the 20th Century, return to power. PRI candidate Enrique Pena Nieto, who has a big lead in the polls, held a final rally in his home state. Rivals Andres Manuel Lopez Obrador of the PRD and Josefina Vazquez Mota of the governing PAN also addressed thousands of their supporters. Mexicans will also be voting on Sunday for Congress and some state governors. Wednesday's rallies capped a long, expensive and at times bitter election campaign, which officially began three months ago. Among the key issues for voters is the drug violence that has led to more than 50,000 deaths. But for many Mexicans, boosting economic growth is more important.