Michelle Bachlet, Chile’s first female president, is expected to dominate the primaries on Sunday. But the candidate who finishes behind her will have a head start in the next election. (Roberto Candia/AP)

SANTIAGO, CHILE — On Sunday, four nominees from Chile’s center-left coalition, the Nueva Mayoría, will compete in the country’s first presidential primary. The clear frontrunner, former president Michelle Bachelet, has been widely criticized for her administration’s sweeping and ill-prepared overhaul in Santiago’s region-wide public transportation system — a decision she’s calmly admitted was a terrible mistake.

Bachelet can afford to graciously admit to her errors because she is widely expected to win her coalition’s nomination and rout the still-undefined center-right nominee in her bid to return to the presidential palace next January. In fact, she’s so popular that even before she began campaigning in March, more than half of Chileans expected to vote for her.

Still, her three rivals in the primaries are vying fiercely for a second-place showing. They understand that while her election is all but a foregone conclusion, the runner-up will gain the lead in the bid for her job four years from now.

One of them, Andrés Velasco, has already distinguished himself: He one of the most vociferous advocates for primaries, and his name will be on the ballot despite his lack of a political affiliation. Like most Chilean voters, Velasco is an independent, and he has become famous for denouncing the machinations and populist tendencies of Chile’s “old politics.”

His distance from the old and new political parties and his fearless challenge to the post-Pinochet political scene has been disciplined and relentless. The son of a law school dean and amateur race car driver who was expelled from the country by Pinochet in the 1980s, Velasco was uprooted as a teenager, and while living in the United States earned economics degrees from Yale and Columbia. He became a professor at New York University in 1984, a post he left for a chair in the economics department at Harvard’s Kennedy School of Government.

In 2005, he moved back to Chile with his wife, anchorwoman Consuelo Saavedra, where he joined Bachelet’s presidential campaign and later become her finance minister. Now making his first run for office, Velasco has assembled a crowd of advisers quite like himself: cosmopolitan, pragmatic and left-leaning.

He’s unwilling to join the populists who would dump the private pension system or promise to convince lawmakers to convoke a mass constitutional convention. Instead, he’s crusading to reform the political system, and his obvious understanding of public policy clearly worries his adversaries.

The issues dividing those who belong to the Nueva Mayoría, a coalition that now includes the Communist Party, tend to center on the administration of social programs. Velasco shares the view that the health system, pension program and educational system need an overhaul, and better financing.

But he goes further and suggests that the country’s indigenous groups that have endured poverty and discrimination for centuries should be able to rely on the resources of a development bank of their own.

Finally, Velasco stands virtually alone on social issues, supporting not only gay marriage and medically necessary abortion, but also adoption by same-sex couples.

In my mind, he is clearly Chile’s best choice to run the country. But to get there, he’ll have to convince voters of the need for profound political reform. He’ll need the communists and student activists who staged massive street protests of 2011 to win seats in Congress. But if that does happen, Chile could become a regional example of reform, thanks to the lessons of its star professor.

Celia Cussen is a professor of Latin American history in Santiago, Chile. She is the author of the forthcoming book, ‘The Life and Afterlife of Martín de Porres, Afroperuvian Saint,’ and is currently researching African slavery in colonial Chile. Follow her on Twitter at @Celia_Cussen.