If you are over 40 then you know that shit began almost 30 years ago. There was always acrimony between the two parties but when the Cold War ended, both parties needed to reassess their agenda and
both started down the path they are on today: politically extreme and mostly serving a minority view within their own parties. It's why there are more Independents than in either party.
The Democrats are as responsible for electing Trump as the Republicans will be for electing Biden. It's a Yin-Yang relationship that is increasingly dysfunctional. The parties won't fix themselves so it will have to be "We, the People" as a group working together in order to put us on a better course. Right now almost 70% of Americans believe we are on the wrong course.
https://www.realclearpolitics.com/epolls/other/direction_of_country-902.html