A poll published by the Brazilian research firm Datafolha on Tuesday found that conservative presidential frontrunner Jair Bolsonaro expanded his lead by two points since being stabbed at a campaign rally last week.

The poll also found a significant decline in the number of undecided voters and that Bolsonaro’s supporters were the least likely to consider other candidates.

Bolsonaro is running a campaign centered around eradicating corruption, upholding conservative social values, and promoting individual freedom, including the promotion of expanded gun rights. He is currently recovering in a hospital in Sao Paulo after a man identified as Adelio Bispo de Oliveira stabbed him in the abdomen at a campaign event Thursday in Minas Gerais, southeastern Brazil.

Datafolha found that Bolsonaro’s lead among other candidates increased from 22 to 24 percent between the latest poll and the one before it, taken on August 20 and 21, giving him more than double the number of votes than the second-place candidate, Marina Silva of the left-wing environmentalist Sustainability Network party, who received 11 percent of the vote. Silva is down from 16 percent support in August.

Three other candidates — Ciro Gomes of the Democratic Labor Party (PDT), Geraldo Alckmin of the Brazilian Social Democratic Party (PSDB), and Fernando Haddad of the Workers’ Party (PT) — were all within the margin of error of each other.

Bolsonaro is the only solidly right-wing, conservative candidate on the ballot, which explains why 74 percent of people who said they would vote for him are not considering any other candidate, the most of any of the contenders. Another notable change in the polls is the number of individuals who said they would file a blank ballot (voting is compulsory in Brazil, so those who wish not to participate must file blank votes). The number of people abstaining from supporting any candidate dropped from 22 percent to 15 percent.

Only about seven percent of voters said they are completely undecided, though many of those voting for a leftist candidate said they would be open to changing their minds. This flexibility could endanger Bolsonaro’s campaign as Brazil requires a second run-off election between the top two candidates if no candidate receives over 50 percent of the vote. Leftist voters are likely to unite behind the non-Bolsonaro candidate.

Before the conservative candidate’s rise, the most popular contender in the Brazilian election was Luiz Inácio Lula da Silva, the former PT president governing during the nation’s biggest corruption scandal, known commonly as “Operation Car Wash.”

Under Lula and, later, successor Dilma Rousseff, Brazilian politicians of all parties were found to have been taking kickbacks from public contractors for infrastructure projects that the politicians overbilled them for, guaranteeing they would always win bids on the projects.

The discovery of the scheme led to millions-strong protests around the nation. Lula is banned from participating in the presidential election and all other public offices in the country after being found guilty and sentenced to 12 years in prison for accepting bribes.

The PT made its final bid to overrule the ban on Lula’s candidacy shortly before Datafolha took its latest poll. Lula, from prison, urged voters to support Haddad in October in a letter published Tuesday.

Marina Silva, in conversation with the Brazilian newspaper O Globo and magazine Época, made clear that she was not seeking votes from Lula supporters. In her remarks, published Tuesday, she referred to Lula as “corrupt” and insisted, “he is being punished for grave corruption crimes.” Lula’s supporters dispute his guilt and claim his imprisonment is the product of opposition corrupt forces trying to keep him out of the election.

Silva also took the opportunity to attack Bolsonaro for his support for gun rights. “From a political point of view, I disagree on security issues. Bolsonaro’s proposals were not weakened by any speech, but by an act,” she told the editors. “Thank God that person [Bispo de Oliveira] didn’t have a firearm. Bolsonaro was with several armed police, personal security, and that did not protect him … if it didn’t work for him, is it going to work for you, housewife?”

Bolsonaro’s sons Eduardo and Flavio, both also legislators, have taken over the campaign while he recovers. Flavio Bolsonaro updated observers on Twitter that his father ate his first meal since being stabbed last week, a small bread roll and juice, on Tuesday, suggesting that he is recovering rapidly from intestinal damage caused by the stabbing.

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