He’s been running for president in Mexico for more than a decade. He’s floated amnesty for drug criminals. Could he win?

One of Mexico’s most controversial and resilient political figures formalized his bid for the presidency Tuesday, vowing if elected to wean Mexico off U.S. agricultural imports, increase aid for students and the elderly and consider amnesty for drug war criminals.

The announcement by leftist Andres Manuel Lopez Obrador was a surprise to no one. AMLO, as he is known to his hordes of supporters and detractors, has been running for president for well over a decade.

The mayor of Mexico City from 2000 to 2005, he narrowly lost to Felipe Calderon in the 2006 presidential race. Six years later, Lopez Obrador was defeated by Enrique Peña Nieto, who leaves office next year. Mexican presidents serve a single six-year term.

This time around, Lopez Obrador is leading in the polls, with a recent one showing him 12 percentage points ahead of his nearest rival. With Peña Nieto’s dismal approval ratings dragging down his ruling Institutional Revolutionary Party, or PRI, and voters anxious about rising homicide rates, high-profile corruption scandals and tense relations with the United States, Lopez Obrador and his supporters think the moment is right for his populist message.

“Third time’s the charm,” he recently tweeted.

But as the lineup of his likely opponents has come into focus, it’s become clear that the 64-year-old with silvery hair has a long battle ahead of him.

How he fares in the July 1 election will depend in no small part on his own ability to stay focused on his message and avoid gaffes.

Lopez Obrador’s recent off-the-cuff declaration that he would consider offering amnesty to those involved in the drug trade who agreed to rehabilitation was a reminder to many of his tendency to sometimes speak too freely. A recent poll found two-thirds of Mexicans disapproved of the proposal, which was publicly rebuked by several of Mexico’s top defense officials.

“He’s a master of self-sabotage,” said Mexican political writer Alejandro Hope. “He’s not disciplined enough.”

Lopez Obrador floated the amnesty idea again during a speech to supporters Tuesday after he officially filed as a presidential pre-candidate, this time saying he would first consult with victims of the drug war. With Mexico on track to record the highest number of killings in nearly two decades, Lopez Obrador said he would “explore all the possibilities to stop the violence.”

What he sometimes lacks in discipline he makes up for in name recognition. Lopez Obrador became the face of the Mexican left thanks to his two previous campaigns and the months-long protest he led in the main square of Mexico City after his 2006 loss, which he blamed on vote fraud.

Jose Antonio Meade, a Yale-educated former finance minister and the likely PRI candidate, has an impressive background in energy and the economy but is unknown to much of the Mexican public. His party, which has held power for all but 12 of the last 88 years, has been damaged by recent corruption scandals involving the president’s family and several prominent governors.

Ricardo Anaya is the likely candidate for an unusual coalition formed by his conservative National Action Party, or PAN, and the left-leaning Democratic Revolution Party, which Lopez Obrador broke from in 2014 to lead his own party, the National Regeneration Movement. It has run candidates in elections across the country.

Also in the mix is Margarita Zavala, a longtime PAN member — and the wife of former President Calderon — who left the party this fall to run as an independent.

The outcome of the race could have big consequences for the U.S., which cooperates with Mexico on matters of security, immigration and trade. The two countries, along with Canada, are locked in tense renegotiations over the future of the North American Free Trade Agreement.

That pact, which abolished tariffs on goods moving between the countries and helped transform Mexico from a smaller, inward-looking economy to one of the world’s leading manufacturers, was for years a top target of Lopez Obrador, who blamed it for emptying Mexico’s countryside of farmers and fueling migration to the U.S.

He now says keeping the agreement is important to Mexico’s stability — but his opponents have sought to paint him as a radical leftist akin to the late Venezuelan leader Hugo Chavez.

On Tuesday, Lopez Obrador told his supporters that while maintaining a relationship of friendship and cooperation with the U.S. is important, “we will not accept the mistreatment of migrants, or racist, hegemonic or arrogant attitudes.”

He also pledged to help Mexican farmers and ranchers compete with cheap imports from the U.S., promising subsidies, low-cost fertilizers and set prices for some crops. “In short, we are going to produce the food we consume in Mexico,” he said.

His nationalist platform has drawn comparisons to President Trump. So has his frequent name-calling of rivals. This week, he made headlines when he tweeted a photo of himself stuffing meat into a taco and a dig at Anaya and Meade. “Besides not visiting villages and hearing from the people, the spoiled rich kids of the power mafia miss out on succulent barbacoa,” he wrote.

But while Lopez Obrador has gone to lengths to portray himself as a man of the people who will stamp out the corruption of Mexico’s ruling elites, some complain that he has given few examples of how he’ll fix the problems.

“He projects an image of austerity that contrasts with the offensive ostentation of the rest of the political class,” academic Jesus Silva-Herzog Marquez recently wrote in Reforma newspaper. “What is striking is the absence of concrete proposals to combat such a complex problem.

“The faith that Lopez Obrador has in Lopez Obrador explains his tenacity, his resistance, his secrecy, his coherence, his sectarianism,” Silva-Herzog said. “He has suffered a thousand injustices but has not been wrong once.”

kate.linthicum@latimes.com

Twitter: @katelinthicum

Cecilia Sanchez in The Times’ Mexico City bureau contributed to this report.