Andres Manuel Lopez Obrador, presidential candidate for the Democratic Revolution Party, greets supporters during the closing rally of his campaign at the main Zocalo plaza in Mexico City on Wednesday. Mexico will hold presidential elections on Sunday. (Associated Press)

Andres Manuel Lopez Obrador, presidential candidate for the Democratic Revolution Party, greets supporters during the closing rally of his campaign at the main Zocalo plaza in Mexico City on Wednesday. Mexico will hold presidential elections on Sunday. (Associated Press)