Pollsters fail to capture Bolsonaro support again in Brazil vote

Four years later, Brazilian pollsters once again underestimated support for Jair Bolsonaro. 

With just over 99 percent of votes tallied on Sunday evening, the right-wing president had about 43 percent of the votes, propelling him to an October 30 run-off against heavy favourite Luiz Inácio Lula da Silva, who took over 48 percent of votes. 

The day before the election, two of Brazil’s most closely followed pollsters Datafolha and Ipec had Bolsonaro at 36 percent and 37 percent, respectively, when removing null and blank votes in the first round. And they indicated there was a real chance of Lula winning outright on Sunday evening. 

In 2018, Bolsonaro, 67, rose from the fringe of Congress to the nation’s top job on a shoestring budget, flouting the airwaves and traditional campaign methods while dominating the race on social media. Pollsters failed to fully capture his support in their numbers. This time around, it must be said, surveys were more accurate in projecting Lula’s support. 

“We prevailed over the lies,” Bolsonaro told reporters Sunday evening in Brasilia, in reference to the polls.

There are multiple reasons an opinion survey could fail to gauge the real support for Bolsonaro. Fervent followers could refuse to talk to pollsters they don’t trust, more moderate supporters might be embarrassed to say they support the often-crass leader, or there may have been last-minute decisions to change a vote from a candidate that was running far behind the front-runners. 

Andrei Roman, head of polling firm AtlasIntel, says many survey companies botched their calls on Bolsonaro, in part, because they over estimated the amount of poor voters, who tend to support Lula. Brazil has not conducted a census since 2010, leaving pollsters to come up with estimates for representative samples of things like religion and household income, that best reflect the electorate.

“The samples were always wrong, they were inflating the poor,” Roman said. “Even we underestimated Bolsonaro.” The last Atlas poll projected Bolsonaro to receive just over 41 percent of the total votes against more than 50 percent for Lula.

The surveys also undershot his ability to transfer support in local races. Bolsonaro has shown his backing makes a big differences for candidates for Senate, governor and Congress, Oliver Stuenkel, a professor of international relations at the Getúlio Vargas Foundation in São Paulo, wrote on Twitter.

"Lula is still the favourite to win the run-off. But just like Trump,Bolsonaro has shown that his support makes a big differences for candidates for Senate, Governor and Congress.That will make it harder for centre-right politicians to challenge Bolsonaro's hegemony over Brazil's right, " wrote Stuenkel.

Some of the biggest botched calls of the evening came in the state of São Paulo, the most populous, where Fernando Haddad, Lula’s Workers’ Party candidate for the presidency last election, was the favourite to take the governorship. He finished nearly seven percentage points behind Bolsonaro’s former infrastructure minister Tarcisio de Freitas, with the two heading to a run off. Similarly, in the state’s Senate race, former astronaut and Bolsonaro’s ex-science minister Marcos Pontes clinched an unexpected victory.

In the southern state of Rio Grande do Sul, Bolsonaro’s former Vice-President Hamilton Mourão surprised and trounced the Worker’s Party candidate in the senate contest. The incumbent’s ex-human rights minister Damares Alves also won a Senate seat in the capital, Brasilia.