Today, September 7, Brazil is celebrating two centuries of independence from Portugal. Soon afterward, on October 2, more than two hundred million Brazilians will elect their next president.

With rival challengers failing to gain traction, most voters will likely choose between two of Brazil’s best-known politicians: current president Jair Messias Bolsonaro, who is struggling for reelection after four tumultuous years, and former president Luis Inácio Lula da Silva of the left-wing Workers’ Party (PT), who is aiming for an unprecedented (and nonconsecutive) third term.

With Brazilian society deeply polarized between supporters of the far-right incumbent, who refuses to say whether he will accept an electoral defeat, and his center-left challenger, the election is certain to test Brazil’s weakened democratic institutions.