"Unless she commits to making a game-changing level of investment in improving policing and reducing impunity, Sheinbaum will likely struggle to achieve a significant improvement in overall levels of security," said Nathaniel Parish Flannery, an independent Latin America political risk analyst.

 

The ruling MORENA party also won the Mexico City mayorship race, one of the country's most important posts, according preliminary results.

Among the new president's challenges will be tense negotiations with the United States over the huge flows of U.S.-bound migrants crossing Mexico and security cooperation over drug trafficking at a time when the U.S. fentanyl epidemic rages.

 

Mexican officials expect these negotiations to be more difficult if the U.S. presidency is won by Donald Trump in November. Trump has vowed to impose 100% tariffs on Chinese cars made in Mexico and said he would mobilize special forces to fight the cartels.

 

At home, the next president will be tasked with addressing electricity and water shortages and luring manufacturers to relocate as part of the nearshoring trend, in which companies move supply chains closer to their main markets.

 

Sheinbaum will also have to wrestle with what to do with Pemex, the state oil giant that has seen production decline for two decades and is drowning in debt.

 

"It cannot just be that there is an endless pit where you put public money in and the company is never profitable," said Alberto Ramos, chief Latin America economist at Goldman Sachs. "They have to rethink the business model of Pemex."

 

Lopez Obrador doubled the minimum wage, reduced poverty and oversaw a strengthening peso and low levels of unemployment - successes that made him incredibly popular.

 

Sheinbaum has promised to expand welfare programs, but it will not be easy with Mexico on track for a large deficit this year and sluggish GDP growth of just 1.5% expected by the central bank in 2025.

 

Lopez Obrador has loomed over the campaign, seeking to turn the vote into a referendum on his political agenda. Sheinbaum has rejected opposition claims that she would be a "puppet" of Lopez Obrador, though she has pledged to continue many of his policies including those that have helped Mexico's poorest.

 

In her victory speech, Sheinbaum thanked Lopez Obrador as "a unique person who has transformed our country for the better".

 

But political analyst Viri Rios said she thought sexism was behind criticism that Sheinbaum was going to be a puppet of the outgoing leader.

 

"It's unbelievable that people cannot believe she's going to be making her own decisions, and I think that's got a lot to do with the fact that she's female," she said.