President-elect Luiz Inácio Lula da Silva made a stunning political comeback by defeating incumbent Jair Bolsonaro. But he could face a short honeymoon — and a long four years in office.

Brazilians head to the polls Sunday to vote in a presidential election that is testing the world's fourth-largest democracy and could have a critical impact on the fight against climate change.

Luiz Inácio Lula da Silva, the left-wing former president, won more votes than right-wing incumbent President Jair Bolsonaro, but not enough to win outright in the 11-candidate race.

As one of the world's largest democracies heads to the polls on Sunday, here are the main candidates and issues in the Brazilian election.

Jair Bolsonaro is relying on support from the country's quickly growing evangelical community to pull off an upset against former President Luiz Inácio Lula da Silva in October.

The move could pave the way for Luiz Inácio Lula da Silva to run against an increasingly vulnerable President Jair Bolsonaro in next year's election.