Which is why the polling is showing up the way it is.Trump's share of the total vote in 2016 was 46%. Just for furn, I went and looked at all the election wins by popular vote for the last 100 years and I can't find an instance of a president winning by a lower share of the total vote in an election without a strong 3rd choice like in 1992 with Ross Perot.
Trump and his supporters by extension his supporters, really are the little man behind the Wizard of Oz.
List of United States presidential elections by popular vote margin - Wikipedia
Edit: With that said, Dems make it harder on themselves by nominating flawed candidates like Hillary in 2016 and a guy who is not well like Joe Biden in 2020.
Unlike Hillary, I don’t think the people saying they will vote for Biden will have second thoughts coming up to the deadline. There’s no “what do I have to lose, I guess I’ll try something different” factor this election. Everyone knows who Trump is now.