The other thing that an under count of republicans in polls does to
a campaign like Biden's is to stop them, if they thought they were way ahead in certain states, from more aggressive messaging. If they knew what four % points of Trump supporters were thinking, the ones who were 'shy', their campaign would have ended much differently. If you have the wrong data how can you land your campaign perfectly on election day? The word came in the last week of the campaign that there were 'shy' republicans. No doubt the info came from republican numbers. Democrats better figure it out.
= new reply since forum marked as read
and what the state's population is, factoring in the age demographic who were eligible, you would see that there were whole segments of the voting-age population not participating (or perhaps only doing so every 4 years or maybe every 2 years if there is a mayoral or gubernatorial election).
Through my lifetime living in this state, I always got the sense (and that includes experiences from some limited travel around the state) that most people seemed to be more of the "we mind our own business" types. They weren't overtly in-your-face "political" but believed what they believed. It wasn't something all-consuming or in the forefront.
But it seems that after 2010, a shift happened for the worse, or at least some "element" here got amplified, it infected a number of other people including newly elected officials, and that seems to have slowly taken a relatively "low-keyed" state, and lit it up.
There have always been what I called the "annoying Republicans" but this crew has literally devolved into foaming-at-the-mouth ingrates. 
They like the "bravado" and the ability to "tell it like it is". He is the "bully" they admired back in high school because he got what he wanted when he wanted and rarely got disciplined for it. They didn't care what he would be fighting about, just that he fought. 
The canvassers are on the far right... the far left of the camera is showing the scanning machines, so when they're done removing ballots from envelopes and flattening, they'll hand them off to scanner operators who will run them through! It's hard to see but there are people going all the way back on that far right shot. Most of the observers are seated over on that side (off camera).
YEP!
FDT!
