** FILE ** Presidential candidate Enrique Pena Nieto waves to supporters at his party's headquarters in Mexico City early on Monday, July 2, 2012. Mexico's old guard sailed back into power after a 12-year hiatus Sunday as the official preliminary vote count handed a victory to Mr. Pena Nieto, whose party long was accused of ruling the country through corruption and patronage. (AP Photo/Christian Palma)

Photo by: Christian Palma

** FILE ** Presidential candidate Enrique Pena Nieto waves to supporters at his party's headquarters in Mexico City early on Monday, July 2, 2012. Mexico's old guard sailed back into power after a 12-year hiatus Sunday as the official preliminary vote count handed a victory to Mr. Pena Nieto, whose party long was accused of ruling the country through corruption and patronage. (AP Photo/Christian Palma)