Pollsters point to technical tie in Brazil election run-off

As the Brazilian presidential runoff approaches on October 25, a critical election day, polls have indicated a near dead heat between incumbent leftist Luiz Inácio Lula da Silva and right-wing challenger Flávio Bolsonaro. On Thursday, three days before the decisive second round between the two rivals, nearly all major opinion polls showed a statistical tie, with the margin of difference nestled within the margin of error.

This narrow contest has cast doubt on earlier polls that initially underestimated Bolsonaro's performance. Lula, who entered the election with a slight edge in most forecasts, saw Bolsonaro surge ahead with 47.03 percent of valid votes (56,104,503 ballots) compared to Lula's 45.15 percent (53,879,538 ballots). This outcome has compelled pollsters to refine their models to account for the reduced field of candidates (only Bolsonaro from the Liberal Party versus Lula of the Workers’ Party) and heightened voter volatility.

The final televised debate, scheduled for the eve of the election, remains a pivotal factor that could sway voter sentiment. The latest poll conducted by PoderData, based on 4,000 telephone interviews across 865 municipalities, revealed a statistical tie, with Bolsonaro at 49 percent and Lula at 48 percent. The margin of error in this survey is 1.6 percentage points, meaning the two candidates are virtually neck and neck.

When excluding blank and spoiled ballots, Bolsonaro would lead by a margin of just 1.12 percentage points. Another polling firm, Quaest, projecting a similarly tight race, found Bolsonaro with 45 percent and Lula with 44 percent of support. These projections align with the margin of error. The polling agencies Bloomberg utilizes, Atlas Intel, also forecast a close contest, with Bolsonaro at 49.8 percent and Lula at 47.6 percent of voter intentions, based on a sample of nearly 5,000 respondents.

The two other surveys conducted earlier this week produced comparable tight results. Real Time Big Data, surveying 1,500 people, projected Bolsonaro at 48 percent and Lula at 45 percent, while BTG/Nexus, polling 3,000 individuals, estimated 46.5 percent for Bolsonaro and 45.9 percent for Lula, both within the poll's margin of error.

The latter projection suggests a slight edge for the challenger, with Flávio winning the run-off at 50.3 percent compared to Lula's 49.7 percent.