**Brazil's compulsory voting system for citizens aged 18-70 continues to support elevated first-round participation near historical levels of 79% in 2022 and 2018.** Recent TSE data shows 14% of the electorate now holds optional status due to expanded numbers of voters over 70 and lower youth registration, which historically correlates with modestly higher abstention. September surveys highlight emotional drivers such as loneliness and digital fatigue contributing to disengagement, particularly among younger cohorts, while the tight contest between Lula and Flávio Bolsonaro—locked in statistical ties across recent polls—provides mobilization incentives. These offsetting dynamics position 78-80% turnout as the consensus range among traders, with adjacent brackets reflecting uncertainty over whether competition fully offsets demographic and behavioral headwinds ahead of the October 4 vote.