Claudia Sheinbaum won a landslide victory to become Mexico’s first female president, inheriting the project of her mentor and outgoing leader Andres Manuel Lopez Obrador whose popularity among the poor helped drive her triumph.

Sheinbaum, a climate scientist and former mayor of Mexico City, won the presidency with between 58.3% and 60.7% of the vote, according to a rapid sample count by Mexico’s electoral authority. That is set to be the highest vote percentage in Mexico’s democratic history.

The ruling coalition was also on track for a possible two-thirds super majority in both houses of Congress, which would allow the coalition to pass constitutional reforms without opposition support, according to the range of results given by the electoral authority.

Opposition candidate Xochitl Galvez conceded defeat after preliminary results showed her taking between 26.6% and 28.6% of the vote.

“For the first time in the 200 years of the republic I will become the first woman president of Mexico,” Sheinbaum told supporters to loud cheers of “president, president”.

Victory for Sheinbaum is a major step for Mexico, a country known for its macho culture and home to the world’s second biggest Roman Catholic population, which for years pushed more traditional values and roles for women.

Sheinbaum is the first woman to win a general election in the United States, Mexico or Canada.

“I never imagined that one day I would vote for a woman,” said 87-year-old Edelmira Montiel, a Sheinbaum supporter in Mexico’s smallest state Tlaxcala.

“Before we couldn’t even vote, and when you could, it was to vote for the person your husband told you to vote for. Thank God that has changed and I get to live it,” Montiel added.

Sheinbaum has a complicated path ahead. She must balance promises to increase popular welfare policies while inheriting a hefty budget deficit and low economic growth.

After preliminary results were announced, she told supporters her government would be fiscally responsible and respect the autonomy of the central bank.

She has vowed to improve security but has given few details and the election, the most violent in Mexico’s modern history with 38 candidates murdered, has reinforced massive security problems. Many analysts say organized crime groups expanded and deepened their influence during Lopez Obrador’s term.

Sunday’s vote was also marred by the killing of two people at polling stations in Puebla state. More people have been killed – over 185,000 – during the mandate of Lopez Obrador than during any other administration in Mexico’s modern history, although the homicide rate has been inching down.

“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.