New book on how Biden barely won

[neostassenite31]

Got my copy yesterday. It's pretty interesting how much this book trashes public polling showing Biden winning by "huge margins" and their insistence that private internal polling on both sides were very accurate in predicting a close race hinged on just a couple of states.

I wonder if this is mostly hindsight bias or reflective of an actual chasm between what's publicly available versus what the campaigns see