I think people are also under estimating the level of effort Trump has put into maintaining his base. He, with far more regularity than a president probably should this far from an election, is often out in some blue collar town giving rallies at the same time the dems are doing something. Nearly always in swing states.
https://en.wikipedia.org/wiki/List_of_post-election_Donald_Trump_rallies---
"History Is Much Like An Endless Waltz. The Three Beats Of War, Peace And Revolution Continue On Forever." - Gundam Wing: Endless Waltz