Carlos Bolsonaro’s (PL) decision to relocate from Rio de Janeiro and run for one of Santa Catarina’s two Senate seats has fragmented right-leaning support and created internal PL tensions ahead of the October 4, 2026 vote. Local resistance to the outsider candidacy, including criticism that it sidelines figures like Esperidião Amin, has boosted Carol de Toni’s (PL) position in some polling while leaving both candidates with substantial undecided or rejection shares. Multiple lower-polling contenders further dilute the field. Traders price a narrow edge for Carlos in first place amid these dynamics, with separation likely hinging on party consolidation, turnout among bolsonarista voters, and any late shifts in alliances or campaign momentum before election day.