Andres Manuel Lopez Obrador, the progressive former mayor of Mexico City, won a landslide victory in Mexico's national elections last Sunday. Lopez Obrador has promised to end politics as usual — and the resulting corruption — in his country. His victory is a milestone in Mexican politics, but the parliamentary majority of his Movement for National Regeneration (MORENA) is key to his ability to remake his country. His supporters are delighted; detractors warn that the leftist firebrand's policies will usher in chaos and undermine progress in the economy.

Lopez Obrador has run for president three times. In 2006, after losing by half a percentage point, Lopez Obrador charged that he had been robbed and refused to accept the results. The street protests that followed and the establishment of a "Cabinet of Denunciation" convinced many that he was an anti-democratic extremist and his political career was over. Undaunted, he ran again in 2012, losing this time by a 6.6 percent margin.

Last weekend, he rode a tide of popular disgust with corruption and incompetence to the largest electoral margin in a presidential election in over three decades, winning 53 percent of the popular vote and beating the second-place finisher by nearly 30 percentage points.