Fresh off a corruption firestorm at home that sank his popularity to the lowest level of his presidency, Argentina's Javier Milei is flying straight into an uproar over bank fraud in Brazil.The risk to his reputation may be a price worth paying if it helps to topple his archrival and Latin America's most prominent leftist. Argentina's libertarian leader is set to appear Saturday at a Liberal Party convention in Sao Paulo that will formally launch Flavio Bolsonaro's bid to unseat President Luiz Inacio Lula da Silva in Brazil's October vote.Also read: Brazil emerges as major rare earths source for IndiaOn Thursday, Brazil's Supreme Court authorized police to look into Bolsonaro's alleged ties to the man at the center of a massive bank fraud probe roiling Latin America's biggest economy. He has denied wrongdoing. The investigation threatens to further upend Bolsonaro's candidacy in the October election, as the right-wing senator already trails Lula by 7 percentage points in an AtlasIntel poll published this month.It's the highest-stakes bet in the region by Milei, who has sought to make himself a force on the global right, and basked in the conservative victories of Peru's Keiko Fujimori, Colombia's Abelardo de la Espriella and Chile's Jose Antonio Kast.