Mauro Mendes (União Brasil) holds a commanding lead in the race for first place in Mato Grosso’s October 4 Senate election, where voters select two senators. Recent September 2026 polls, including Paraná Pesquisas, show him at 52–55% in stimulated scenarios allowing two choices, far ahead of Janaina Riva (MDB) at 31–35% and trailing candidates such as Zé Medeiros (PL), Carlos Fávaro (PSD), and Pedro Taques (PSB). Mendes benefits from high name recognition and consistent support as the state’s former governor through 2026. The remaining field remains fragmented with single-digit or lower support, leaving little room for late shifts before voting. Trader pricing aligns with this polling hierarchy and the short timeline to election day.