Presidential candidate Enrique Pena Nieto of the Institutional Revolutionary Party casts his vote with his wife Angelica Rivero de Pena on July 1, 2012 in Atlacomulco, Mexico. Mexicans went to the polls to choose a new president and vote in thousands of state and local posts nationwide. Daniel Aguilar / Getty Images

Enrique Pena Nieto, presidential candidate for the Revolutionary Institutional Party shows his ink-stained thumbs after he cast his vote during general elections in Atlacomulco, Mexico, Sunday, July 1, 2012. Mexico PRI candidate Pena Nieto leads with about 40 percent of vote, according to first exit polls. Dario Lopez-Mills / AP