Governor Eduardo Riedel has opened a sizable early advantage in Mato Grosso do Sul’s 2026 race, but the large share of undecided voters in the unprompted survey underscores how far the campaign still has to run.

The Real Time Big Data poll places Riedel of the PP at 44% in a prompted first-round scenario, compared with 25% for Fábio Trad of the PT. The gap is narrower in the spontaneous measure—24% to 10%—where 51% of respondents said they did not know or did not answer. That contrast suggests Riedel has stronger name recognition and a clear current edge, while much of the electorate has yet to settle on a candidate.

The institute’s head-to-head simulation offers an even more favorable reading for the incumbent: Riedel would defeat Trad by 54% to 32%. The report says he “maintains the advantage and would win the direct contest.”¹ For Trad and the opposition, the figures point to the challenge of converting voters who are not yet engaged in the race rather than merely closing a conventional polling deficit.

The Senate contest has a similar frontrunner but a tighter battle behind him. Former governor Reinaldo Azambuja of the PL leads with 38%, ahead of fellow PL candidate Capitão Contar at 19% and Nelsinho Trad of the PSD at 15%. With two seats at stake, Azambuja appears best placed for the first vacancy, while the second remains contested among the next-ranked candidates.²

Real Time Big Data interviewed 1,600 voters from August 1 to 5, 2026. The institute, which funded the survey itself, reported a 95% confidence level and a two-percentage-point margin of error; the poll was registered with Brazil’s electoral court as MS-07706/2026.¹ As an early snapshot rather than a forecast, it measures the race’s current balance—not the eventual result.