Self-sure pollsters were considerably off the mark with their predictions concerning the 2016 and 2020 presidential elections. Some anticipate their predictions will soon be proven wrong again because much of the extant data is likely based on surveys of registered Republicans and Democrats, both similarly unrepresentative of vast swathes of the electorate.
Although pollsters may have been misled by Republican respondents misrepresentative of the tens of millions of Trump-friendly voters in past elections, this year, the New York Times indicated it may be the participation of overexuberant Biden Democrats, Biden Republicans, and Biden independents who have artificially pumped up Democrats' chances nationwide.
The Times reported that "Biden voters, regardless of their party, were probably likelier to respond than Trump voters," of which there were at least 73.5 million two years ago.