I made a politics/economic model mixed with an elo pollster rater that was right in all states by 4% margin. I predicted 3.8% advantage for Biden Only instead of 4.5% and called 3 wrong states (Wisconsin, Georgia and Arizona), but all could be right if my national vote advantage for Biden was right. And would be if I knew the real gdp 2020 growth annd unemployment rate like we know now.
I think Bolsonaro polls have the same problem. Today was out one where he would lose 66-34,but I remember when he had 30% in first round 3 days before 2018 election in some polls and had 46%.