All eyes are set on Sunday October 7 presidential election, but Brazilians will also be electing, 27 governors, 54 senators and 513 legislators, and Congress wields considerable power and since 2016 has decided the fate of two presidents: to impeach Dilma Rousseff for juggling with budget numbers and to shield Michel Temer from corruption charges.
Currently, more than 25 parties, most of which lack any clear ideology, often led by important regional and national power brokers, are represented in the lower house. As a result, horse trading is common: parties support bills in return for patronage...and also cash as happened during the first mandate of ex president Lula da Silva.
The current Congress is also highly conservative. After the 2014 election, analysts described it as the most conservative since Brazil's military dictatorship with the rise of the powerful agricultural, evangelical Christian and law enforcement blocks, known collectively as the Bullets, beef and bible caucus. Experts see 2018's elected Congress as retaining this profile or likely getting more conservative.
We will have a strong and active block of the hard right wing in Congress, the strongest since the dictatorship, said Sylvio Costa, founder of watchdog group Congress in Focus. Regardless of whether Bolsonaro wins or loses, he will have a strong parliamentary support.
Costa said that he thought it likely that the Bullet Caucus made up of legislators mostly from law enforcement backgrounds - that seeks to increase gun ownership and advocates a tough stance on crime - would increase its numbers in the lower house, riding the wave of Bolsonaro's success that has in part been fuelled by increasing violent crime.
Costa also expects the evangelical Christian caucus, which wants to tighten Brazil's already restrictive abortion laws by making terminations illegal even in the case of rape, to increase its power.
The churches are very organized, he said.
This week, Brazil's powerful agricultural caucus which has 261 members of 594 in Congress declared its support for Jair Bolsonaro, who has described rural workers groups like the Landless Workers' Movement (MST) as terrorists and wants loosen gun laws.
Congresswoman Tereza Cristina, president of the Agriculture Parliamentary Front (FPA), also running for re-election, said the caucus was: attending to the call of the national productive sector, from individual entrepreneurs to small farmers and representatives of big business.
But regardless of who wins the presidency, Brazil's Workers' Party is also confident it can maintain a strong presence in the lower house and Senate.
It's important that we maintain a strong base in Congress to counter the conservatives, said Eduardo Suplicy a veteran Workers' Party member and renowned human rights advocate, leading the race for senate in Sao Paulo.
Despite being rocked by years of scandals, the left-leaning Worker's Party continues as the preferred party for 23% of Brazilians with the centre-right Social Democracy Party and far-right Bolsonaro's Social Liberty Party the preferred of 35%.
Experts say that the highly divided Congress will cause serious problems of governance and passing of much needed fiscal reforms with Brazil barely limping out of a recession and near record high unemployment.
Whoever is elected will face great difficulties, both Haddad and Bolsonaro have very high rejection rates, their political capital after the elections will be limited because of this polarization, said Rafael Cortez, a political scientist at Tendencias Consultancy in Sao Paulo.
According to local media reports, this year, between 80/85% of representatives are running for reelection.
New campaign finance rules which ban donations from companies - drawing instead from a public fund, a measure introduced to tackle corruption, will favor established candidates.
Of 55 legislators targeted under investigation or facing accusations in Brazil's far-reaching Lava Jato corruption probe, 50 will try for re-election. Congress members get legal immunity and can only be tried for crimes like corruption in Brazil's slow-moving Supreme Court.
Tens of thousands of candidates run each election and unconventional candidates are a long-standing tradition.
In 1988, three years after a military dictatorship ended, a well-known chimpanzee named Tiao at Rio de Janeiro zoo received 400,000 votes, finishing third place for mayor.
In 2010, TV clown Tiririca was the country's most voted-for congressman with 1.3 million votes, needing just 304,000 to get elected, and he took another three candidates to Congress with him because representatives can pass on excess votes to their coalition.