Brazilians call him SuperMoro, chanting his name on the streets of Rio de Janeiro as if he were a soccer star. But Sergio Moro is just a judge, albeit one prosecuting a corruption scandal so huge it could bring down a President—and perhaps change a culture of graft that has long hobbled his country’s progress.

Operation Car Wash, as his investigation is called, found that kickbacks were paid to middlemen and politicians in exchange for contracts at Petrobras, the state-run oil company. The money is huge, but even bigger is the political impact, with hundreds of lawmakers under investigation. Although she hasn’t been directly linked to any bribery, President Dilma Rousseff now faces impeachment in part because of Moro’s work.

Moro has been accused of ignoring due process, and he’s been more than willing to try his cases in the court of public opinion. But most Brazilians feel that his sharp-elbowed tactics are worth the trade-off for a cleaner country.

Walsh is the international editor for TIME

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