Marília Arraes (PDT) holds a commanding lead in the market for second place in Pernambuco’s Senate election due to consistent polling strength through late September and early October 2026. Surveys from Datafolha, AtlasIntel, and Quaest placed her alongside Humberto Costa (PT) at the top of combined first- and second-choice intentions, supported by high name recognition as the granddaughter of former governor Miguel Arraes, her record as a federal deputy, and the Frente Popular alliance’s “voto casado” strategy. Mendonça Filho (PL) trailed as the primary challenger, while other candidates remained fragmented below 15%. Late-campaign momentum and voter preference consolidation reinforced trader expectations. A significant late swing in turnout among right-leaning voters or an unexpected surge by Mendonça Filho or Eduardo da Fonte could still alter the final ordering before certification.