Andrés Manuel López Obrador (ändrās´ mänwĕl´ lō´pĕs ōbrädôr´), 1954–, Mexican politician. A lawyer, he was active in the Institutional Revolutionary party (PRI) in the state of Tabasco, but he left the PRI and in 1988 helped form the leftist Democratic Revolutionary party (PRD). In 1996 he was an unsuccessful candidate for the Tabasco governorship, but fraud may have contributed to his defeat. Four years later he was elected mayor of Mexico City, becoming a highly visible and popular PRD leader. As mayor he promoted social programs but was often at odds with the city assembly and sometimes governed by decree. In 2004 he was charged with ignoring court orders in a land dispute and was arrested, but the federal charges were seen as a politically motivated move to prevent him from running for president in 2006 and were dropped. He was indeed the PRD's presidential candidate in 2006 and was also favored to win, but narrowly lost to Felipe Calderón. Accusing the National Action party of stealing the election (a charge not supported by independent observers), he refused to concede, and his supporters staged large protest rallies for several weeks after the election. He was the PRD's candidate for the 2012 presidential election, and again placed second (to the PRI's Enrique Peña Nieto) and rejected the results. López Obrador subsequently left the PRD to focus on transforming the National Regeneration Movement (Morena), a grassroots group of his supporters, into a political party (registered 2014).