The "middle" was independent voters too embarrassed to claim the GOP, but still voted for Trump overwhelmingly. That "middle" doesn't exist anymore.
Third-party candidates collectively won around 4% of the vote in Pennsylvania and 6% of the vote in Michigan and Wisconsin in 2016, enough to sway those races, which were decided by less than a point, and hand President Trump an electoral college victory despite Hillary Clinton’s 2 percentage point lead in the national popular vote.
Only 1.8% of voters said they back a candidate besides Biden or Trump in a Suffolk University poll of 1,000 registered in late August, a significant drop from the more than 5% who voted third party in 2016, which could have a significant impact on how the race plays out in states where third-party candidates helped shape the race in 2016.
Biden is also far more popular than Clinton was, and Trump has galvanized Republicans behind him and boosted his favorability rating since 2016, meaning the bloc of voters who view both candidates unfavorably – the primary source of votes for third-party candidates – is much smaller.
No matter how many times you go on the internet and say "this is how you make a liberal turn fascist" doesnt make it true.