In early 2018, as Mexico’s presidential election heated up, photos began circulating online. They showed murals that had sprung up in Venezuela, signed by the country’s United Socialist Party, supporting the populist Mexican candidate Andrés Manuel López Obrador. 

After the pictures made headlines, the López Obrador campaign scoffed at the suggestion of a Venezuelan connection and accused opponents of engineering the whole thing. The incident was just one example of how misleading political content proliferated across social media in the run-up to the election. One analysis found that bots and influencers generated nearly one-fifth of content on Twitter in Mexico in March 2018. 

Nearly three years later, Mexican journalists are gearing up for a localized fight against political disinformation ahead of the country’s June midterm elections, where voters will pick candidates in Congressional, gubernatorial, and state legislative races.

The election season has journalists on alert. Expecting a fresh surge of political disinformation, the independent Mexican digital media outlet Animal Político is teaming up with six newsrooms in the states of Chihuahua and Sinaloa to monitor and verify election-related information. The project is the latest iteration in a multi-newsroom fact-checking initiative called Verificado 2018, which worked throughout the 2018 election period to debunk false claims and then stopped publishing when the race came to a close.

Tania L. Montalvo, Animal Político’s deputy editorial director, says disinformation was “key” in the 2018 campaign. False rumors about voter registration requirements and Pope Francis’ distaste for a leading candidate proliferated online; campaigns accused opponents of bankrolling troll armies to push political smears; and former U.S. national security adviser Lt. Gen. H.R. McMaster even weighed in on the race, alluding to a possible Kremlin effort to sway the election.

This time around, the election is less nationalized than the 2018 presidential race — with voters casting their ballots for governors and state officials, among others, so Montalvo expects a more local flavor of political disinformation. “In 2018, with Andrés Manuel López Obrador as a candidate, all the disinformation was about him,” she told me. “That was very national. And right now this election, it’s very local. We have a lot of local candidates and disinformation is about those movements.” 

The Animal Político team collaborated with newsrooms in Chihuahua and Sinaloa because they are regions with high levels of organized crime and violence against journalists, Montalvo explained — pressures that can make fact-checking especially difficult for local reporters.

Additional challenges for fact-checkers involve allegations that candidates are engaged in drug trafficking, Montalvo said — which can be impossible to verify — or when the government spreads information journalists can’t confirm. She cited an example from the 2018 presidential race, when the government of then-president Enrique Peña Nieto opened an investigation into an opposition candidate, Ricardo Anaya, over money laundering — allegations Anaya categorically denied as a political hit job to discredit his campaign. 

Nieto’s administration ultimately closed the investigation after the election, Montalvo said, but by then, “it was too late for journalists. It was impossible to verify. Access to the investigation, access to any proof, it was completely closed. And I think that investigation really affected the election.”