Former president and candidate Luiz Inácio Lula da Silva with supporters on Saturday in Sao Paulo.
Credit...Victor Moriyama para The New York Times
Former president and candidate Luiz Inácio Lula da Silva with supporters on Saturday in Sao Paulo.

In 2019, Luiz Inácio Lula da Silva was spending 23 hours a day in an isolated cell with a treadmill in a federal penitentiary.

The former president of Brazil was sentenced to 22 years on corruption charges, a conviction that appeared to end the storied career of the man who had once been the lion of the Latin American left.

Now, freed from prison, the former union leader was back in the spotlight and trying to retake the wheel of Latin America’s largest nation, at 217 million people, with a mission to undo President Jair Bolsonaro’s legacy.

When he left office in 2011 after two terms, Mr. da Silva’s approval rating topped 80 percent. But then he became the centerpiece of a sprawling investigation into government bribes that led to nearly 300 arrests, landing him in prison and seemingly destined for obscurity.

Mr. da Silva’s return to the president’s office would cement his status as the most influential figure in Brazil’s modern democracy. A former metalworker with a fifth-grade education and the son of illiterate farm workers, he has been a political force for decades, leading a transformational shift in Brazilian politics away from conservative principles and toward leftist ideals and working-class interests.

As president from 2003 through 2010, Mr. da Silva’s administration helped lift 20 million Brazilians out of poverty, revitalized the nation’s oil industry and elevated Brazil on the world stage, including by hosting the World Cup and Summer Olympics.

But it also allowed a vast kickback scheme to fester throughout the government, with many of his Workers’ Party allies convicted of accepting bribes. Mr. da Silva was convicted of accepting a condo and renovations from construction companies bidding on government contracts. In 2021, Supreme Court ruled the judge in his cases was biased and annulled his convictions, though the ruling did not affirm his innocence.

Mr. da Silva has long maintained that the charges were false.

Overall, Mr. da Silva’s campaign was built around the promise he has been pitching for decades: He will make life better for Brazil’s poor. The pandemic battered Brazil’s economy, with inflation reaching double digits and the number of people facing hunger doubling to 33 million. He has pledged to widen the safety net, increase the minimum wage, lower inflation, feed and house more people and create jobs through big new infrastructure projects.

“He was the anti-poverty president, and that’s the legacy he wants to keep if he wins,” said Celso Rocha de Barros, a sociologist who wrote a book about the Workers’ Party.

Yet, like most successful politicians, Mr. da Silva’s speeches were often short on details and long on promises. He frequently built his rhetoric around a clash between “they,” the elites, and “we,” the people.

“He’s the candidate of the people, of the poor,” said Vivian Casentino, 44, a cook draped in the red of the Workers’ Party, at a rally last month in Rio de Janeiro. “He’s like us. He’s a fighter.”