**Esperidião Amin (PP)** holds the narrowest lead in recent polling for first place in Santa Catarina’s October 4 Senate contest, followed closely by **Carlos Bolsonaro (PL)** and **Carol de Toni (PL)**, with the three names separated by single digits inside the margin of error. The race remains tight because voters can cast two ballots, undecided and blank/null responses stay elevated, and the top contenders draw from overlapping right-leaning bases while competing for distinct regional and party support. Amin benefits from incumbency and a “catarinense para catarinense” message, while the PL ticket leverages the Bolsonaro name and state-government alignment. Further separation is most likely to come from the next round of statewide surveys, intensified television and radio time, or late campaign events that shift undecided voters or consolidate second-preference support before election day.