Regarding the discrepancy between the last Atlas poll in São Paulo and the election results, AtlasIntel clarifies that the electoral trend changed due to the controversy arising from the disclosure of a forged medical document by candidate Pablo Marçal.

We believe that, without this event, Pablo Marçal would have secured a second round against Guilherme Boulos, a result that only the Atlas survey clearly indicated, outside the margin of error between the candidates. According to our analyses, the controversy shifted some voters from Marçal to Ricardo Nunes, slightly affected Guilherme Boulos's performance, and mobilized a wave of strategic voting against a second round between Marçal and Boulos.

The collection of the last Atlas poll took place according to its registration with the TSE (Brazil's Superior Electoral Court), between September 29 and October 4, and had already been concluded at the time of the mentioned situation. All surveys published during the electoral period require prior registration with the TSE, which is why another poll capturing the impact of this last-minute event could not be conducted.