President Trump built his political brand in part on bashing Mexico. Now his second presidency depends on deepening partnerships with the country.

© Emily Elconin for The New York Times

President Claudia Sheinbaum has sharply limited the use of cellphones and screens in schools. The measures will go into effect in November.

© Daniel Becerril/Reuters

Our reporter Emiliano Rodríguez Mega visits the highly polluted Endhó Dam, which some call Mexico’s toilet bowl. People who live nearby say that sickness is everywhere.

For decades, the Mexican authorities have sacrificed a rural valley to flush away the capital’s waste and power the economy. Now, local communities are paying for that decision — often with peoples’ lives.

© Alejandro Cegarra for The New York Times