Bots and Trolls at Play In Mexican Elections

biggest prize is the presidency, with five candidates competing to succeed President Enrique Peña Nieto for a six-year term.

Fake news has been flowing fast, and the campaigns have traded accusations that they have hired paid, online agitators called trolls and used automated programs known as bots to flood social media platforms with messages intended to deceive and manipulate voters.

And as investigators in the United States try to learn the extent of Russian efforts to sway the 2016 presidential election, the threat of Russian interference has loomed over the race here too.

In a speech in December, Lieutenant General H. R. McMaster, then the United States national security adviser, said there were “initial signs” that the Russian government was trying to influence the Mexican election.

Mexican officials say they have not found evidence of Russian meddling or received any from their American counterparts, and the Russian authorities have denied engaging in such activity.

But Enrique Andrade, with Mexico’s National Electoral Institute, said the agency was on guard against any interference. “We do think it is a possibility, and we are preparing ourselves so that it will not affect the process,” he said.

Some analysts believe Russia might still try to disrupt the region by intensifying political polarization in Mexico. And, they say, the Russians may view Andrés Manuel López Obrador, the front-runner in the polls who has cut a more antagonistic figure toward the United States than his rivals, as a useful vehicle for that goal.

Manuel Cossío Ramos, a digital strategist, claims to have found Russian fingerprints on social media traffic concerning the election, much of it about Mr. López Obrador. Mr. Cossío is not affiliated with a presidential campaign, but said he was no fan of Mr. López Obrador.

Using an analytics tool called NetBase, Mr. Cossío said he found that 4.8 million items about Mr. López Obrador had been posted to social media and news websites in April by users outside Mexico. About 63 percent were associated with users in Russia, he said, and 20 percent with Ukraine.

Searches for two other leading candidates, Ricardo Anaya and José Antonio Meade, found most foreign activity was coming from America, with only 4 percent emanating from Russia, Mr. Cossío said.

But other digital consultants said they had found no such evidence of election- related social media activity from Russia, and Mr. Cossío’s findings could not be independently verified.

Officials with Mr. López Obrador’s campaign have dismissed his findings as biased.

Mr. López Obrador has answered the charges of Russian links with satire, posting a video on Twitter showing him waiting in Veracruz for a Russian submarine to bring him “gold from Moscow.”

The pieces of fake news that have circulated in Mexico include a claim that Pope Francis criticized Mr. López Obrador’s political ideology. (He didn’t, according to Verificado 2018, a fact- checking group.)

A Mexican web developer, Iván Santiesteban, concluded that around 20,000 bots were used in the month and a half before Election Day 2012 to create online conversations favorable to Mr. Peña Nieto.

Since then, the online audience has nearly doubled, to about 71.3 million internet users in Mexico, up from 40.9 million in 2012. At the same time, the campaigns have become more adept at designing online strategies.

“From this point on, the battle will be fought on the social networks,” said Javier Murillo, chairman of Metrics, a digital technology consultancy in Mexico.

Using proprietary algorithms, Mr. Murillo said he found that bots and trolls generated up to 27 percent of election postings on Facebook and Twitter in Mexico during a recent monthlong period.

Consultants with the campaigns of the three leading presidential candidates — Mr. Lopez Obrador, Mr. Anaya and Mr. Meade— denied they were using such methods, or spreading fake news.

Mexican authorities have agreements with Facebook, Twitter and Google on ways to counteract fake news and spread accurate information. Facebook, as part of its agreement, placed ads in Mexican newspapers this spring providing guidance on how to detect fake news.

Election officials have been particularly worried about rumors that seem intended to undermine the system’s integrity. The message concerning voter registration this year was of the biggest concern to them so far, Mr. Andrade said.

“Then again,” he cautioned, “we are only getting started in terms of the campaign process.”