Flávio Bolsonaro maintains a commanding lead in Santa Catarina voter preference for the October 25 presidential runoff, backed by consistent polling margins of 25–35 points over Lula in state-specific surveys throughout September and early October. The southern state’s conservative electorate has aligned strongly with the PL candidate and the broader bolsonarista movement, reinforced by local party strength including Governor Jorginho Mello’s reelection and PL gains in Senate races. First-round results already showed Flávio ahead by more than 20 points in partial counts. Recent endorsements from other right-leaning candidates have further consolidated support ahead of the runoff. A late national swing or unusually high turnout among Lula-leaning voters in urban areas could narrow the gap, though current evidence points to durable state-level advantages for the frontrunner.