Sílvia Cristina (PP) and Dr. Fernando Máximo (PL) lead the contest for second place in Rondônia’s October 4 Senate election, with recent Quaest polling placing them at 16% and 18% combined intentions respectively amid 27% undecided voters. The PL’s dual candidacy with Bruno Bolsonaro Scheid fragments right-leaning support, while Sílvia gains ground in first-vote scenarios and Mariana Carvalho (Republicanos) remains competitive in second-vote distributions. High rejection levels for several frontrunners, voter indecision, and the mechanics of casting two distinct Senate ballots sustain the tight positioning reflected in trader consensus. Scheduled debates or further polling shifts on regional priorities such as mining policy could widen gaps before election day.