President of Mexico Andrés Manuel López Obrador held a big rally in Mexico The city’s largest square was visited by tens of thousands of people last Saturday.

Although it was called to commemorate Mexico’s expropriation of the oil industry in 1938, many of those who attended Saturday’s demonstration agreed that it was the de facto opening salvo to the 2024 elections that will choose the president’s successor.

Perhaps aware of recent tensions with United States over US overdose deaths from fentanyl smuggled in from Mexico, López Obrador spent part of his speech praising former US President Franklin Delano Roosevelt, who did not actively oppose the 1938 oil expropriation even though many of the companies were American.

“The best example of the authenticity of his ‘good neighbor’ policy was his respect for our nation’s sovereignty,” López Obrador said of Roosevelt.

It could be one of the last rallies to be led by López Obrador, who is known for his folksy style and charisma. The process to nominate a presidential candidate for his Morena party will begin later this year. After that, the party’s candidate will probably take center stage.

But most agree that few presidential hopefuls can match the popularity of a president whose approval rating routinely tops 60%. This is especially true of the Morena party, which was largely built around López Obrador.

Alberto Martínez, 59, said he hoped Mexico City Mayor Claudia Sheinbaum would be the party’s nominee. “We like her education, her caution,” Martinez said. But he would settle for whoever Morena chose.

Most polls show Sheinbaum as the front-runner, followed by Foreign Minister Marcelo Ebrard.

“The important thing is that López Obrador’s ideology continues,” Martínez said. “This train is already moving, someone just needs to get on board and drive it.”

Former president Lázaro Cárdenas, one of López Obrador’s heroes, delighted Mexicans when he expropriated the largely foreign-owned, privately run oil industry on March 18, 1938.

One of López Obrador’s main policy initiatives has been to save the state-owned oil company that Cárdenas founded from crushing debt and low oil production.

Those who attended the demonstration in the Zocalo wholeheartedly endorsed López Obrador, who has taken a nationalist stance, drastically reducing the ability of US anti-drug agents to operate in Mexico.

Blas Ramos, 69, an electrical engineer, held up a sign that read “Get out of Mexico, FBI, CIA, Gringos!”

He said the president was right to oppose U.S. calls to designate Mexican drug cartels as terrorist organizations or to use the U.S. military to crack down on the gangs.

“They are hypocrites,” he said of American politicians who demand such measures, “because they are not doing anything to reduce drug consumption” in the United States.

The synthetic opioid fentanyl, which kills about 70,000 Americans a year, is mainly manufactured in Mexico with precursor chemicals smuggled in from China.

López Obrador has argued that Mexico does not produce fentanyl — something most experts disagree with — and that the United States has a fentanyl problem because American families don’t hug their children enough.

Ramos was confident that the president’s movement, which he calls “the fourth transformation of Mexico,” would not end when he leaves office in September 2024.

“This is a movement that started a long time ago,” he said. “We have spent our whole lives waiting for this movement.”

“This movement is not over in six years,” Ramos said, referring to the length of presidential terms in Mexico. “This is a process that will take 30, 40 years.”