Claudia Sheinbaum Is Turning Mexico’s Presidential Election Into a Blowout

She would also create a national investigative police force and reduce the military’s power.

Concerns over security are part of the campaign conversation as Mexico prepares for its largest ever election, with voters choosing national offices all the way down to the municipal level.

Since June, Laboratorio Electoral, an independent research institute focused on democracy and elections, has documented at least 67 attacks, threats, kidnappings and killings related to the elections. At least 39 people have been slain, 19 of them candidates for local positions. A significant portion of the violence is linked to cartels and other criminal groups seeking to influence who holds office.

Looming over the race is the presidential campaigning unfolding in the United States. While President Biden’s re-election would signal continuity, a victory by Donald J. Trump, the Republican front-runner, could upend Mexico’s politics by making the country’s reliance on trade with the United States into a source of vulnerability.

Mr. Trump’s campaign is pursuing a proposal for a universal tariff of 10 percent on imported goods. Such a tariff would “present the next president of Mexico, whomever she is, with a challenge that AMLO and his predecessors didn’t face,” said Andrew Rudman, director of the Mexico Institute at the Washington-based Woodrow Wilson International Center for Scholars.

Mr. López Obrador himself could be another destabilizing factor if his protégé wins the presidency. His plan, as he has claimed multiple times, is to disentangle himself from politics and move to a ranch in Palenque, in the southern state of Chiapas, that his parents left him and his siblings.

Many in Mexico have a hard time believing that Mr. López Obrador could just fade into the sunset.

“A character the size of Andrés Manuel López Obrador, the capacity that he had to mobilize emotions and, with that, make up for many of his government’s shortcomings — well, Claudia Sheinbaum is not going to have that,” said Blanca Heredia, a political analyst. “And it will be difficult not to compare her, especially at the beginning, with him.”