Mexico election

Enrique Pena Nieto, presidential candidate of the Revolutionary Institutional Party, or PRI, greets supporters after casting his vote in Atlacomulco, Mexico. (Esteban Felix / Associated Press)

July 1, 2012 9:20 PM PT

PRI candidate Enrique Peña Nieto is leading his nearest competitor, leftist Andres Manuel Lopez Obrador, by about 6 percentage points.

Presidential candidate Enrique Pena Nieto of the Institutional Revolutionary Party casts his vote with his wife, Angelica Rivero de Pena, in Atlacomulco, Mexico. (Daniel Aguilar / Getty Images)

Mexican President Felipe Calderon and his wife, Margarita Zavala, show their ink-stained thumbs after voting in Mexico City in the presidential election.

(Yuri Cortez / AFP / Getty Images)

An indigenous voter casts her ballot during the Mexican presidential elections in the town of San Juan in the state of Morelos. (John Moore / Getty Images)