A combination of file photos shows Brazil's President Luiz Inácio Lula da Silva in Brasília on Oct. 1, 2026, and presidential candidate Flávio Bolsonaro at a rally in Belo Horizonte on Aug. 17, 2026. The two face off in the Oct. 25 runoff. Evaristo Sa and Gledston Tavares/AFP via Getty Images hide caption

Evaristo Sa and Gledston Tavares/AFP via Getty Images

RIO DE JANEIRO — Sunday's presidential runoff in Brazil could prolong the career of a political giant—or usher in a new generation of a political dynasty.

Voter energy has surged ahead of the runoff, with rallies for each candidate drawing tens of thousands of people in major cities and packing plazas and university campuses nationwide

Many polls show a race within the margin of error between left-wing President Luiz Inácio Lula da Silva and right-wing Sen. Flávio Bolsonaro, the son of jailed former President Jair Bolsonaro.

Flávio Bolsonaro finished ahead of Lula in the first round of voting on Oct.…