What to know as Brazilians choose between Lula and Flávio Bolsonaro on Sunday

RIO DE JANEIRO — Brazil is on the cusp of granting leftist incumbent Luiz Inácio Lula da Silva a fourth presidential term or pivoting to the far right again by electing Sen. Flávio Bolsonaro, an ally of U.S. President Donald Trump.

Lula, who at 80 is one of the world’s oldest heads of state, is Brazil's 35th and 39th president, having served from 2003-2010 and again since 2023. Bolsonaro, 45, aims to return his family name to power while his father serves time for attempting a coup to prevent the end of his 2019-2022 presidency.

The younger Bolsonaro bested Lula by more than 2.2 million votes in this month's first round, but neither won an outright majority, setting up Sunday's runoff. Bolsonaro had 47% of the votes to Lula's 45%, and surveys show the race remains tight as voters return to the polls.

Here’s what to know about Brazil’s runoff vote.

From union worker to thrice-elected president

Lula, who got his start as a union worker, losing a pinky finger in a factory accident at 19, inspired cult-like devotion during his first and second terms in office as Brazil's economy expanded with the help of a commodities boom and direct cash assistance that lifted millions of Brazilians out of poverty.

He later spent more than a year in prison on corruption convictions that were eventually annulled before winning a third term in 2022.

Former U.S. President Barack Obama once called Lula “the world’s most popular politician,” but his approval ratings have fallen as low as 24% this term as voters raise concerns about crime and the cost of living. He's responded with promises to share the benefits from extracting Brazil's rare minerals and other resources and has increased payments through his flagship Bolsa Familia program by 15%.

Other steps Lula has taken to shore up support before the runoff include cutting fuel taxes, pardoning the government debts of 3.6 million small businesses, moving to block cellphone signals around prisons, and proposing to boost welfare payments to university students.

And with just days to go before this vote, Brazil’s Senate approved rules backed by Lula's administration to reduce the maximum workweek from 44 to 40 hours while enshrining two rest days without a salary cut.

A lawyer following in a father's footsteps

Sen. Bolsonaro began his political career at 21, when he became Rio’s youngest elected state lawmaker.

With former President Jair Bolsonaro barred from running as he serves a 27-year sentence under house detention, his eldest son has largely embraced his father’s ultra-conservative agenda while trying to moderate his communication style to attract centrist voters.

His hard-line security policies have been a pillar of his campaign, and polls show these proposals are popular. The senator has pledged to fight criminal groups by building El Salvador-style megaprisons, to follow the Trump administration’s lead by designating transnational gangs as terrorist organizations and to try defendants as young as 16 as adults.

Brazil plays a vital role in mitigating global warming by protecting the Amazon rainforest, but deforestation hit a record high during Bolsonaro's presidency, and his son has likewise denied human-caused climate change, committing only to stopping illegal deforestation.

Sen. Bolsonaro’s admission that he accepted millions of dollars from disgraced banker Daniel Vorcaro to produce a film on his father’s life has cast a shadow over his campaign. He is under investigation for corruption, money laundering and tax evasion in connection with the case.

Trump looms large

Lula has repeatedly warned the U.S. not to meddle in Brazil’s elections and has made defending Brazil's sovereignty a key campaign issue. The Trump administration did not respond to a request for comment on whether it is seeking to influence the outcome, but he has repeatedly made gestures favoring his ally.

Trump announced 50% tariffs on Brazilian goods last year, citing — among other reasons — the trial of Jair Bolsonaro. This year, he imposed a new round of U.S. tariffs, citing unfair trade practices despite running a U.S. surplus. Trump also classified Brazil’s biggest drug-trafficking groups as foreign terrorist organizations shortly after receiving Sen. Bolsonaro at the White House — a move Lula's administration opposed as a pretext for intervention.

A victory by Sen. Bolsonaro would add Brazil to a list of Latin American countries — including Argentina, Chile, Colombia, Costa Rica and Peru — that have elected Trump-friendly governments in recent years.

Voting in Brazil is mandatory

Brazil also held its first round of voting for state and federal lawmakers on Oct. 4, and candidates who won more than 50% of valid votes, which exclude blank and spoiled ballots, were confirmed. Joining Lula and Bolsonaro on runoff ballots are governors in five states and the federal district.

Voting in Brazil is mandatory, and almost 160 million Brazilians are called to the polls. But more than 33 million, or 21% of the electorate, did not vote earlier this month, and could face a small fine for failing to cast a ballot without justification. People who missed the first round can vote in the second.

Brazilians cast ballots using electronic voting machines, punching in digits that correspond to their candidates. Results are reported within hours after polls close.