On the 1 July, Mexicans will go to the polls in a crucial election. All opinion polls show that a victory for the candidate of Morena (Movement for National Renewal), Andres Manuel Lopez Obrador (AMLO) is quite likely. However, nothing is certain in Mexico. The ruling class has already used election fraud to cheat AMLO out of winning the elections twice and will certainly try a third time. In this article, the comrades from the Mexican section of the IMT – La Izquierda Socialista – explain why they advocate a critical vote for Lopez Obrador, address the limitations of his programme and assert the need to organise to struggle against capitalism (read the original, Spanish-language article here).