Wisdom after the event — the only polls that were wrong appear to be Fox, Rasmussen and Gallup
They weren't wrong, they just didn't, and don't have even the vaguest understanding as to the extent of democrat cheating. The democrats had so much confidence that they were going to win they didn't even care if there wasn't enthusiasm, crowds or anything else. They knew that they had the old strategy for cheating and some new ones that we don't even know about. The next election will likely be the same unless something drastic happens.
They actually glory in cheating just like they do every other sin. They are becoming more wicked every day.