Datafolha poll shows tight race between Lula and Flávio in the runoff

The first Datafolha poll measuring the second‑round contest between Senator Flávio Bolsonaro (PL) and President Luiz Inácio Lula da Silva (PT) will be released this Thursday, after a first round that left Flávio ahead with 47.03% of valid votes against 45.16% for Lula.

Details of the Datafolha poll

The survey, commissioned by Grupo Globo and Folha de S. Paulo, will be carried out Tuesday‑Wednesday, with 2,520 face‑to‑face interviews. The margin of error is two percentage points and the confidence level 95%. The registration with the Electoral Court is under code BR-02949/2026.

Campaign strategies for the runoff

Flávio counts on the support of São Paulo Governor Tarcísio de Freitas (Republicanos) and aims to widen his advantage in the state, while traveling the country on a schedule yet to be defined. The campaign bets on Lula’s wear‑out, portraying him as an outdated political figure.

Lula, in turn, seeks to reinforce his base in the Northeast and intensify the presence of Vice‑President Geraldo Alckmin to attract centrist voters.

Destination of third‑party votes

With the two candidates for the runoff set, attention turns to the roughly 9.3 million voters who backed Augusto Cury (Avante), Renan Santos (Missão) and Ronaldo Caiado (PSD) in the first round. The BBC indicates that the transfer of these votes is likely to favor Flávio, since the pool of votes for Lula is limited.

Quaest polls point out that Flávio should receive the bulk of the voting intentions from Cury, Renan and Caiado supporters. Among these voters, the abstention or blank‑vote rate is also high, ranging from 27% to 41%.

Impact of the “useful” vote from minor candidates

Poder360 highlights that the useful vote – voters who abandoned their preferred candidate to back the one with better chances – was decisive for Flávio’s first‑round lead. Candidates polling below 6% have dried up in recent days, shifting about 3.42 percentage points to Flávio.

In practice, the sum of votes for Cury, Renan, Caiado and Zema accounted for 7.58% of valid votes, but the gap between that total and the sum of polling intentions indicates migration toward Flávio.

Next steps in the campaign

The runoff campaign starts this Monday and will run until the eve of voting, scheduled for October 25. The candidates will have equal airtime on radio and TV, and the first face‑to‑face debates are slated for the coming days.

With information from O GLOBO, BBC, Poder360.