The new course marks a dramatic shift from his predecessor.

On July 1, leftist politician Andres Manuel López Obrador—often referred to with the acronymic AMLO—won the Mexican presidency in a landslide. When he takes office in December, with his party in control of both houses of the Mexican Congress, Mexico’s drug policies are likely to see some radical changes.

Just what AMLO does will have significant consequences on both sides of the border. His policies will impact how much heroin and cocaine make it to the streets of America, as well as how many Mexicans flee north to escape prohibition-related violence, and how much drug money flows back into Mexico, corrupting politicians, police, and the military.

That AMLO—and Mexico—wants change is no surprise. A vigorous campaign against the country’s powerful and violent drug trafficking organizations—the so-called cartels—unleashed by rightist president Felipe Calderon in 2006 brought the Mexican military into the fight, but instead of defeating the cartels, the campaign, still ongoing under President Enrique Pena Nieto, has instead led to record levels of corruption and violence.