I think Dinesh Desousa had the best explanation: “they are all doing their part”. They being the Democrap party and it’s operatives, their media arm, pop culture and sports celebs, tech giants, and Wall St. - the entire Ruling Class. They are of one mind, one culture, one set of values, and hole a common disdain for We The (Deplorable) People.
So in their bubble it is better to go down mouthing the party line than to start backpedaling and showing weakness and insecurity. In a world of blue pillers, nobody want to be the first to take the red pill.
They may be smarter than you think. The expectations laid coming into this, even as total BS, are cover for protracted post-election fighting in a state like PA, or anywhere where fraudulent votes can gain them victory.
So, they are all “doing their part” as part of the Big Con.
Here is the video by Dinesh D’souza (sorry for butchering his name) - in which he explains why the pollsters act as they do and why they will be proven wrong. 3 1/2 minutes well worth watching:
https://www.youtube.com/watch?v=O-RVkGqXFLM