Brazilians vote Sunday in a presidential runoff between Senator Flávio Bolsonaro, a close ally of President Donald Trump, and President Luiz Inácio Lula da Silva. Final polls show a dead heat, while prediction markets favor Bolsonaro.
Bolsonaro, the eldest son of former President Jair Bolsonaro, finished first in the October 4 first round with 47.03 percent of valid votes to Lula's 45.16 percent, defying surveys that had shown Lula ahead. The runoff will decide whether Latin America's largest country joins a growing bloc of right-leaning governments aligned with Washington.
What the Final Polls Show
Bolsonaro's runoff lead has steadily narrowed. Datafolha showed him ahead 52 to 48 percent of valid votes on October 8 and 51 to 49 percent on October 15. Its poll released Thursday had the two tied at 50 percent.
Other recent surveys:
- AtlasIntel/Bloomberg, released October 19: Bolsonaro 51.1 percent, Lula 48.9 percent.
- Quaest, released October 21: Bolsonaro 45 percent, Lula 44 percent of total voting intentions.
- Real Time Big Data, released Friday: Bolsonaro 52 percent, Lula 48 percent.
- Ipespe/Abrapel: Bolsonaro 50.5 percent, Lula 49.5 percent.
- Vox Brasil, released Friday: Lula 50.6 percent, Bolsonaro 49.4 percent.
Nearly all of those results fall within the polls' margins of error. An average compiled by The Rio Times puts Bolsonaro at 50.9 percent and Lula at 49.1 percent.
"Lula has narrowed the gap, but not enough; the margin is very tight and within a dead heat. It could go either way," Gimena Sánchez, director for the Andes at the Washington Office on Latin America, told Newsweek.
How Polls Missed Bolsonaro's First-Round Lead
Most major pollsters had Lula ahead going into the October 4 vote. Datafolha, one of Brazil's most closely watched pollsters, put Lula at 45 percent of valid votes and Bolsonaro at 42 percent in its final survey. AtlasIntel/Bloomberg had Lula ahead 47 to 44.1 percent, and CNT/MDA showed him leading 47.8 to 42.1 percent. Quaest came closest, with Lula up 46 to 45 percent.
Bolsonaro instead finished nearly two points ahead. Compared with Datafolha's final numbers, that was a swing of almost five points toward him.
It was not the first time a Bolsonaro outran the surveys, with his father also beating his polling in 2022.
"I think the polls underestimated that, similar to Argentina, Brazil, and U.S. elections, Bolsonaro has supporters who are not revealing their support until they get to the polls," Sánchez said.
Patricio Navia, a clinical professor of liberal studies at New York University, said that unless pollsters corrected whatever caused the miss, they are likely to repeat it on Sunday, which would favor Bolsonaro. Turnout is the wild card, he noted. Abstention was high in the first round, and Lula has spent the runoff trying to bring new voters out.
What Prediction Markets Say
Prediction markets have been more confident than pollsters. As of Saturday afternoon, Polymarket gave Bolsonaro roughly a 78 percent chance of winning and Lula about 23 percent. Kalshi, which is regulated by the U.S. Commodity Futures Trading Commission, showed similar odds.
Bolsonaro's chances peaked at around 84 percent on Polymarket immediately after the first round.
Part of that confidence rests on history. No candidate who finished second in the first round has gone on to win a presidential runoff since Brazil returned to democracy in 1985.
"If Lula were to win, it would be the most important electoral come back in the history of Brazil," Navia told Newsweek.
How the Campaign Shifted
Finishing second on October 4 jolted Lula's campaign. Michael Shifter, a senior fellow and former president of the Inter-American Dialogue, said the president has since run a more aggressive race, leaning on promises of new government programs and a sharper social media operation.
In their first head-to-head runoff debate, aired by Band on October 18, Lula pressed the Bolsonaro family to open its bank records, and Bolsonaro tried to tie the president to the Banco Master scandal. Few expect it to move many voters.
Debates rarely shift an election unless someone stumbles badly, Navia said, and neither candidate did.
Shifter thought a visibly energized Lula, who turns 81 on Tuesday, may have eased some doubts about his age.
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"I think Lula needed a knockout victory. He didn't get that," Oliver Stuenkel, a professor of international relations at the Getulio Vargas Foundation in São Paulo, told Newsweek.
Still, he said, some Bolsonaro voters from the first round now realize they know little about the senator's agenda "beyond sort of vague security populism and getting his father out of prison."
Sánchez faulted both men for spending the night attacking each other instead of speaking to what voters actually need.
A final debate on TV Globo on Friday night delivered the campaign's most emotional moment. Criticizing the government's economic record, Bolsonaro said Lula gives with one hand and "takes away with nine fingers," a jab at the finger the president lost in a factory accident as a young metalworker.
Lula demanded an apology, tying the remark to workers hurt on the job, and Bolsonaro gave one. "Lula, if I offended you by calling you 'nine fingers,' then I sincerely apologize," he said, before asking whether Lula would apologize to Brazilians in debt.
In his closing remarks, Lula apologized too, for the heated tone he had taken.
"I don't expect even the final debate to have a decisive impact," Stuenkel said.
Bolsonaro's Ties to Trump
Flávio Bolsonaro, 45, has represented Rio de Janeiro in the Senate since 2019. His father, who is in prison after being convicted in 2025 of plotting a coup to overturn his 2022 loss to Lula, picked him as the family's candidate in December.
The senator has cultivated close ties to the Trump administration. He met Trump in the Oval Office in May, along with Vice President JD Vance and Secretary of State Marco Rubio. During that trip, he urged Washington to designate Brazil's two most powerful criminal organizations as terrorist groups, a step the administration announced days later. He has also promised to bring Brazil into Trump's Shield of the Americas security initiative.
The relationship with Washington has also been a liability. Trump's 50 percent tariffs on Brazilian goods in 2025, imposed in part over the prosecution of Jair Bolsonaro, were unpopular in Brazil, and Lula has framed U.S. pressure as an attack on national sovereignty. Flávio Bolsonaro chose not to seek Trump's endorsement, and Trump has largely stayed out of the runoff.
The election is also a major test of Trump's assertive approach to Latin America, a revival of the 19th-century Monroe Doctrine nicknamed the "Donroe Doctrine." It has included the capture of Venezuelan leader Nicolás Maduro in January, financial support for Argentine President Javier Milei and open backing of conservative candidates in the region.
A Bolsonaro victory would make Brazil the eighth Latin American country to elect a right or center-right leader since Trump returned to office in 2025, following wins including José Antonio Kast's in Chile and Abelardo de la Espriella in Colombia.
"Despite sharp differences with some regional counterparts, in broad terms Bolsonaro would fit with the notably conservative trend in Latin America," Shifter said.
Will the Result Be Accepted?
The memory of January 8, 2023, when Jair Bolsonaro's supporters stormed Congress, the Supreme Court and the presidential palace in Brasília, hangs over Sunday's vote.
If Lula wins, Benjamin Gedan, who served as the White House National Security Council director for South America in the Obama administration, told Newsweek he expects false fraud claims from Bolsonaro, whose two political mentors, his father and Trump, are both "paradigmatic election denialists."
Shifter is more optimistic. He expects Lula to accept a loss and believes Bolsonaro, who has pledged to respect the outcome, is unlikely to repeat 2022 because "he is not his father, and the moment is different."
Navia pointed out that fraud was never a centerpiece of Bolsonaro's campaign, which would make any claim after a loss harder to sell.
Either winner inherits sluggish growth and a fiscal deficit that needs reining in, Navia said, with a fragmented, spending-hungry Congress likely to make that harder.
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When Will Results Come In?
Polls open at 8 a.m. and close at 5 p.m. Brasília time (4 p.m. ET) on Sunday. Voting is mandatory for most Brazilians ages 18 to 70.
Brazil uses electronic voting machines nationwide, and the Superior Electoral Court typically reports a winner within a few hours of polls closing. The winner will take office on January 5, 2027.
Contact Newsweek editors for this story: Anthony Murray and Jason Lemon.