Andres Manuel Lopez Obrador becomes Mexico’s new president Saturday.

He enters office in a powerful position with a coalition that controls both houses of Congress.

Lopez Obrador has promised a more austere administration than that of his predecessor Enrique Pena Nieto. Among other things he has said he will sell the presidential plane.

At 65, Lopez Obrador has been a mainstay of Mexican politics. As a young man, he was a member of the center-right Institutional Revolutionary Party, or PRI, which controlled Mexico’s government for eight decades.

Yet in the 1980s, as cracks were beginning to show in PRI’s coalition, Lopez Obrador was one of the many leftist politicians to split from the PRI, joining the Party of the Democratic Revolution, or PRD.

Mayor of Mexico City

In 2000, Lopez Obrador — still a member of PRD — was elected mayor of Mexico City, the nation’s capital and most populated city. In this position, he gained national prominence, instituting social programs for the poor and elderly and improving the city’s infrastructure.

After his mayoral term ended in 2005, Lopez Obrador sought higher office, making his first presidential bid the following year. For much of the race, he was considered the front-runner. Yet, Felipe Calderon of the right-leaning National Action Party, or PAN, narrowly defeated him, labeling the former mayor a socialist in the mold of then-Venezuelan President Hugo Chavez. The label stuck.

In 2012, Lopez Obrador ran for president a second time, but lost to Pena Nieto, of PRI. Pena Nieto, proved unpopular; during his time in office, Mexico’s murder rate swelled to an all-time high, the peso lost value, and Donald Trump was elected U.S. president.

Pence to attend ceremony

Trump has repeatedly used anti-Mexican rhetoric and pledged to build a wall between the two nations. U.S. Vice President Mike Pence will attend Obrador’s inauguration ceremony.

Mexico’s constitution only permits presidents to serve one term; as such, Pena Nieto could not run in this year’s election. Thus Lopez Obrador, running on the newly founded National Regeneration Movement, (MORENA), was able to capitalize on discontent with the country’s status quo and finally claim the presidency.