** FILE ** In this Friday July 14, 2006, file photo, teachers' union head Elba Esther Gordillo gestures as she arrives to attend a meeting with education workers a day after being expelled from Mexico's Institutional Revolutionary Party in Mexico City. (AP Photo/Dario Lopez-Mills, file)
Mr. Pena Nieto's win returns the Institutional Revolutionary Party to the presidential palace after a 12-year absence. His wife, soap opera star Angelica Rivera, will be the new first lady. (Associated Press)
Enrique Pena Nieto, presidential candidate for the Revolutionary Institutional Party (PRI), greets supporters at his party's headquarters in Mexico City early on Monday, July 2, 2012. (AP Photo/Alexandre Meneghini)
Enrique Pena Nieto of the Revolutionary Institutional Party held a significant lead for president as voting was under way Sunday in Mexico's 31 states. His party controlled the Mexican presidency through much of the 20th century before losing the past two elections. (Associated Press)
Enrique Pena Nieto, Revolutionary Institutional Party (PRI) presidential candidate, speaks June 24, 2012 during a massive rally at the Azteca stadium in Mexico City. (Associated Press)
ASSOCIATED PRESS PHOTOGRAPHS
ASSOCIATED PRESS PHOTOGRAPHS
Humberto Moreira (above) is head of the Institutional Revolutionary Party, which ruled Mexico for 71 years until 2000 and is aiming to regain power. However, Treasury Secretary Ernesto Cordero, who wants to be the presidential candidate for the National Action Party, has launched an investigation into finances in Coahuila state, where Mr. Moreira was governor until January.