Thousands of protesters take to the streets in Mexico City on Monday, a day after the presidential election results were announced. Supporters of the opposition candidate were rallying against Enrique Peña Nieto, who declared victory late Sunday. AFP/Getty Images
Peña Nieto, representing the Institutional Revolutionary Party (PRI), speaks during a press conference Monday in Mexico City. He said it was time for his country to leave behind the political rancor of the campaign season. Getty Images
Members of the "I Am 132" movement protest on Monday. A video that was uploaded to YouTube helped launch the nationwide student movement, adding fuel to the political frenzy. AFP/Getty Images
Projected as the runner-up in Sunday's vote, Andres Manuel Lopez Obrado, right, speaks in Mexico City on Monday. He said he was awaiting the official election results and prepared to contest them before judicial authorities if they didn't turn out in his favor. AFP/Getty Images
A youth activist rallies in Mexico City on Monday. About a third of Mexico's 79.4 million registered voters are between the ages of 18 and 29. AFP/Getty Images
Peña Nieto celebrates with his family after projections declared him the apparent victor in Mexico's presidential election on Sunday, July 1. AFP/Getty Images
Peña Nieto's supporters cheer during the victory speech in Mexico City on Sunday. The results would mean a return to power for a party that ruled Mexico for more than 70 years. Getty Images
Peña Nieto greets supporters in Mexico City after polls closed and results stacked in his favor early Monday, July 2. Getty Images
Peña Nieto, whose political party was ousted by the conservative National Action Party in 2000, addresses supporters Sunday. Getty Images
Andres Manuel Lopez Obrador, Peña Nieto's challenger from the Democratic Revolution Party, says he is unwilling to concede in Mexico City on Sunday. AFP/Getty Images
Supporters of Lopez Obrador listen on the streets of Mexico City during his news conference Sunday. AFP/Getty Images
"The last word has yet to be said," Lopez Obrador, a former Mexico City mayor, said Sunday. AFP/Getty Images
Supporters of the Mexican university student movement "I Am 132" protest in front of police outside the national TV network Televisa during a rally against the PRI and Peña Nieto in Mexico City on Saturday. AFP/Getty Images
Protesters supporting the "I Am 132" movement rally outside Televisa headquarters in Mexico City on Saturday. AFP/Getty Images