

Mexicans unhappy with the presidential election results, march in Mexico City on July 7, 2012. The protesters reject the final count in the presidential election showing former ruling party candidate Enrique Peña Nieto as the victor. They believe the Institutional Revolutionary Party (PRI) engaged in vote-buying that illegally tilted millions of votes. PRI officials deny the charge. Marco Ugarte/AP
Andres Manuel Lopez Obrador, presidential candidate for the Party of the Democratic Revolution (PRD), is seen during a news conference in Mexico City on July 9, 2012. The presidential candidate said on July 9 he does not accept the July 1 presidential election results in which he placed second. Edgard Garrido/Reuters
An electoral worker shows a ballot during a recount of votes at a district office of Mexico's Federal Electoral Institute (IFE) in Monterrey on July 5, 2012. Mexican opposition candidate Enrique Peña Nieto maintained his lead in a final count from the July 1 presidential election, confirming initial results published the night of the vote. Daniel Becerril/Reuters
Election officials and party representatives begin a computation of ballot boxes at an electoral institute district council in Mexico City on July 4, 2012. The computation was done to determine which ballot boxes used in the general elections will be recounted in front of party representatives. Eduardo Verdugo/AP
Winning candidate of Mexico’s presidential election, Enrique Peña Nieto arrives to a press conference in Mexico City on July 11, 2012. Peña Nieto announced July 11 he appointed a task force to help him defend the results of the July 1 presidential elections that Mexican presidential candidate Andres Manuel Lopez Obrador is challenging. Eduardo Verdugo/AP
Enrique Pena Nieto, presidential candidate for the PRI or Revolutionary Institutional Party (c.) greets supporters at the party's headquarters in Mexico City, early 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 Pena Nieto. Alexandre Meneghini/AP
Presidential candidate Andres Manuel Lopez Obrador of the Democratic Revolution Party (PRD) leaves the podium after speaking in Mexico City, Sunday, July 1, 2012. Obrador said he won't concede the presidency despite an official preliminary count that shows him losing to former ruling party candidate Enrique Pena Nieto, of the Institutional Revolutionary Party (PRI), and that he would wait for a full count. Eduardo Verdugo/AP
Women look at electoral booklets listing candidates before voting at a polling station in Oaxaca, Mexico, Sunday, July 1, 2012. Mexico's more than 79 million voters head to the polls Sunday to elect a president, who serves one six-year term, as well as 500 congressional deputies and 128 senators. Luis Alberto Cruz/AP
Party operatives of Mexican presidential front-runner Enrique Pena Nieto hold hands while standing on a stage with Pena Nieto at one of his last campaign rallies in Toluca June 27, 2012. Nieto leads in the polls, which may return to power the party that ruled for much of the last century. Tomas Bravo/Reuters
Mexican presidential front-runner Enrique Pena Nieto greets supporters during his last campaign rally in Monterrey, on June 27, 2012. Daniel Becerril/Reuters
Josefina Vazquez Mota, presidential candidate from the ruling National Action Party (PAN), talks to supporters during her last campaign rally at Omnilife stadium in Zapopan, in the outskirts of Guadalajara, on June 27, 2012. Vazquez Mota is trailing in third place in the polls. Alejandro Acosta/Reuters
Andres Manuel Lopez Obrador (c.) presidential candidate for the Democratic Revolution Party (PRD) waves to supporters as he walks towards the main Zocalo plaza during a massive march for the final campaign closing rally in Mexico City, Mexico, on June 27, 2012. Dario Lopez-Mills/AP
Mexican presidential front-runner Enrique Pena Nieto (l.) hugs his wife Angelica Rivera at one of his last campaign rallies in Toluca, on June 27, 2012. Edgard Garrido/Reuters
Josefina Vazquez Mota, presidential candidate from the ruling National Action Party (PAN), greets supporters during her last campaign rally at Omnilife stadium in Zapopan, in the outskirts of Guadalajara, on June 27, 2012. Alejandro Acosta/Reuters
Members of the movement 'Yosoy132' (I am 132) take part in a protest outside TV broadcaster Televisa building in Mexico City June 26, 2012.The YoSoy132 movement was organized by students against the candidature of Enrique Pena Nieto. They also demanded a balance in the media coverage of the presidential race, local media reported. Bernardo Montoya/Reuters
Leftist presidential candidate Andres Manuel Lopez Obrador (c.) shakes hands with supporters during his last campaign rally in Mexico City, on June 27, 2012. Bernardo Montoya/Reuters
A supporter of Andres Manuel Lopez Obrador, presidential candidate for the Democratic Revolution Party (PRD) wears earrings with his photo before the closing rally of his campaign at the main Zocalo plaza in Mexico City, on June 27, 2012. Esteban Felix/AP
Supporters of Andres Manuel Lopez Obrador, presidential candidate for the Democratic Revolution Party (PRD) carry signs as they head towards the main Zocalo plaza to participate in Lopez Obrador's final campaign closing rally in Mexico City, Mexico, on June 27, 2012. Dario Lopez-Mills/AP
A member of the movement 'Yosoy132' wears a mock television box top takes part in a protest outside TV broadcaster Televisa building in Mexico City June 26, 2012. Bernardo Montoya/Reuters
Members of Yosoy132 unfurl a banner during a protest at the Monument of the Angel of Independence in Mexico City June 24, 2012. Tomas Bravo /Reuters
A supporter takes a picture with his iPad of leftist presidential candidate Andres Manuel Lopez Obrador at Zocalo Square during Lopez Obrador's last campaign rally in Mexico City, on June 27, 2012. Bernardo Montoya/Reuters
Supporters of Manuel Lopez Obrador, presidential candidate for the PRD, gesture during a campaign rally in Mexico City on May 21. Eduardo Verdugo/AP
Supporters of Lopez Obrador, presidential candidate of the PRD, rally in support of his candidacy at the Monument of the Angel of Independence in Mexico City on May 20. Bernardo Montoya/Reuters
From left: Presidential candidates Enrique Pena Nieto of the Revolutionary Institutional Party (PRI), Josefina Vazquez Mota of the National Action Party (PAN), Gabriel Quadri of the New Alliance Party (PANAL), and Andres Manuel Lopez Obrador of the Democratic Revolution Party and Workers Party (PRD, PT), pose for a group photo prior to the start of the first presidential debate in Mexico City on May 6. IFE/AP
People watch candidate Pena Nieto, from the PRI, on a giant TV screen during the first televised presidential debate at Mexico City's main Zocalo plaza May 6. Eduardo Verdugo/AP
A couple watches the televised presidential debate in Mexico City on May 6. Eduardo Verdugo/AP
Lopez Obrador, leftist presidential candidate for the PRD, is backdropped by a painting of Benito Juarez, Mexico's first president of Indian descent and national hero, while speaking at a news conference in Mexico City on April 13. Marco Ugarte/AP
Citizens look to a giant screen during the presidential candidates' televised debate at Zocalo Square in Mexico City on June 10, 2012. Mexico's presidential contenders locked horns for a final televised debate with front-runner Enrique Peña Nieto under mounting pressure from student-led opposition. Edgard Garrido/Reuters
Presidential candidates take part in their second televised debate in Guadalajara on June 10, 2012. Participating in the debate are (from r. to l.) Josefina Vazquez Mota of the ruling National Action Party (PAN), Enrique Peña Nieto of the opposition Institutional Revolutionary Party (PRI), Gabriel Quadri of the New Alliance Party (PANAL), and Andres Manuel Lopez Obrador of the Party of the Democratic Revolution (PRD). The moderator for the debate is Javier Solorzano (l.). Instituto Federal Electoral/Reuters
Students belonging to the 132 movement march towards the second presidential debate site in Guadalajara, Mexico, June 10, 2012. Tens of thousands of young demonstrators clogged Mexico City streets June 10 to protest the likely return to power of the country's long-ruling party. Bruno Gonzalez/AP
Manuel Lopez Obrador, presidential candidate for the Democratic Revolution Party (PRD) embraces Maria Gonzalez, mother of two missing children, during a meeting in Mexico City on May 28. Presidential candidates met with Mexican poet Javier Sicilia, leader of the Movement for Peace with Justice and Dignity, and family members of victims of drug gang-related violence. Mexico will hold presidential elections on July 1. Eduardo Verdugo/AP
Enrique Pena Nieto, presidential candidate for the Institutional Revolutionary Party (PRI) attends a meeting with family members of victims of drug gang-related violence, in Mexico City on May 28. Eduardo Verdugo/AP
Presidential candidate Josefina Vazquez Mota of the ruling National Action Party (PAN) greets supporters as she arrives for a meeting with women in Ciudad Juarez, Mexico. Jose Luis Gonzalez/Reuters
A university student holds a placard during a protest against Enrique Pena Nieto, presidential candidate of the opposition PRI, and to demand balance in the media coverage of the presidential race, in Mexico City on May 28. The 'YoSoy132' movement was organized by students to create awareness of Mexico's current political situation and media censorship. The placard reads, 'If you don't study will finish like this.' Edgard Garrido/Reuters
US Vice President Joe Biden and presidential candidate Josefina Vazquez Mota shake hands as they pose for pictures in Mexico City on March 5. Vazquez Mota pledged to become Mexico's first female president. Within weeks of announcing her candidacy she was within single digits of the frontrunner. Alexandre Meneghini/AP
Gabriel Quadri, the presidential candidate for PANAL (r.) and Mexican businessman Alejandro Marti speak during an event organized by Civil Society Mexico to deliver a document about justice and security, in Mexico City on April 2. Alexandre Meneghini/AP
Enrique Pena Nieto, presidential candidate for the PRI, greets supporters during a campaign rally in Nezahualcoyotl, Mexico, April 28. The PRI hopes to return to Mexico's highest office after 12 years out of power. Marco Ugarte/AP
Josefina Vazquez Mota, presidential candidate for PAN, talks with people through the window of her childhood home as part of her official campaign launch in Mexico City. Eduardo Verdugo/AP
Manuel Lopez Obrador, presidential candidate for the PRD, greets supporters as he campaigns in Chalco, Mexico, April 13. Marco Ugarte/AP
Enrique Pena Nieto, presidential candidate for the PRI, greets supporters at a campaign rally in Nezahualcoyotl, Mexico, April 28. Marco Ugarte/AP