PRI
Mexican opposition Senator Gabriela Cuevas on Sunday said she will leave the center-right National Action Party (PAN) to join the campaign of leftist.
Former Mexican governor to be extradited from Panama Jan. 4.
A former Mexican governor wanted on corruption charges was arrested on Friday.
Rules by Mexico's ruling Institutional Revolutionary Party allowing it to form coalitions and non-members to run for president were necessary to stop Obrador.
Mexican President Enrique Pena Nieto on Saturday.