Brazil's President Jair Bolsonaro and his Chief of Staff Ciro Nogueira gesture during a ceremony to commemorate Forro Day, at the Planalto Palace in Brasilia, Brazil December 13, 2021.
Brazil's President Jair Bolsonaro and his Chief of Staff Ciro Nogueira gesture during a ceremony to commemorate Forro Day, at the Planalto Palace in Brasilia, Brazil December 13, 2021. Reuters / UESLEI MARCELINO

Far-right Brazilian President Jair Bolsonaro has seen the ranks of his new party swell in Congress while center-right rivals for the presidency deal with friendly fire, giving the incumbent a boost as he gears up for his re-election campaign.

Bolsonaro's decision to join Brazil's right-wing Liberal Party (PL) last month helped draw a wave of new members, making it the largest party in the lower house of Congress with 75 seats - up from just 33 seats after the 2018 election.

With leftist former President Luiz Inacio Lula da Silva sitting on a large but shrinking polling advantage ahead of the October vote, the popularity contest in Brasilia is a reminder of how the powers of Bolsonaro's office will shape the race.

Fickle centrist parties from the so-called "Centrao," which Bolsonaro once cast as crooked professional politicians, have embraced the president and his re-election efforts since one of their own, former lawmaker Ciro Nogueira, became his chief of staff in July, with final word on key budget decisions.

"The Centrao has taken on Bolsonaro as a political project of their own," said analyst Leonardo Barreto of Vector Consultancy in Brasilia, flagging a gradual uptick for the president's support in polls this year. "Ciro Nogueira has become the great architect of the re-election campaign."

Nogueira's Progressives (PP) and the allied Republicans (PRB), both right-wing parties in Brazil, have also seen their ranks surge in Congress during the window for party affiliation, which closed on Friday.

"They are people who want to surf on the Bolsonaro wave," said political analyst Cristiano Noronha of ARKO consultancy.

By contrast, Bolsonaro's main rivals on the right found themselves at odds with their parties as the window shut.

Bolsonaro's former Justice Minister Sergio Moro, who made a name fighting corruption as a federal judge and broke publicly with the president in 2020, joined the center-right Brazil Union party only to learn its members resisted his presidential bid.

Brazil Union briefly became Brazil's largest party last year when the Democrats (DEM) merged with the conservative Social Liberal Party (PSL), but dropped from 81 lower house members to 48 as Bolsonaro backers left to join government-allied parties.

Sao Paulo Governor Joao Doria, who won the primary for his center-right Brazilian Social Democracy Party (PSDB), had flirted with scrapping a presidential run to stay in office, according to local media, drawing ire from allies.

Ultimately, he declared his intention to run for president on Friday, limping into the race after a day of ugly headlines.

Doria has been polling in low single digits in recent polls of the presidential field, while Moro has drawn high single digits, with some surveys suggesting his support would go largely to Bolsonaro if he left the race.

Even with those rivals weakened, Bolsonaro faces an uphill battle to re-election, as Brazilians remain angry with his handling of the coronavirus pandemic, along with rising inflation and a weak economic recovery.

"He has gained some ground in Congress, but the real thermometer is not there," said Aline Machado, a political scientist studying Brazil's party system.

She underscored Lula's strategic choice of former Sao Paulo Governor Geraldo Alckmin as a centrist running mate: "The ticket has split the right and ruled out any middle alternative between Bolsonaro and Lula," she said.

Neither has formally declared his candidacy. Campaigning for the Oct. 2 vote officially begins in August.