The AMLO Voter: Affective Polarization and the Rise of the Left in Mexico

What prompted so many voters in Mexico to abandon the traditional parties and support MORENA and its candidate, Andrés Manuel López Obrador? This research relies on data from Mexico's National Electoral Study (2018). The results show that support for López Obrador is strongly associated with affective polarization and the perception that the PRI and PAN represented the same political alternative. In turn, retrospective evaluations and ideology were not associated with López Obrador's victory. This research note contributes to our understanding of Mexico's historical elections as well as to the broader literature on the Latin American left. The success of the political left in Mexico is not rooted on voters’ programmatic preferences. Similar to the decay of mainstream political parties in other Latin American countries, in 2018, Mexican voters rejected the mainstream political establishment by supporting Lopez Obrador's third bid for the Presidency.