Boulos, in a last-ditch effort for exposure, on Friday accepted an invitation to debate self-help guru turned far-right politician Pablo Marçal, who finished third in the first round of voting on Oct. 7. At the end of the debate, Marçal urged his voters not to vote Sunday. Lower turnout could work against Nunes.

Most of the attention in this year’s round of municipal elections in Brazil has been on Sao Paulo, where the race was marred by episodes of violence involving Marçal in the first round of voting. Boulos, a longtime housing advocate for the poor, has been campaigning nonstop to avoid his second consecutive defeat in the race.