This article is a fascinating example of the progressive narrative that "We only lost by not being progressive enough." Which is objectively wrong if you look at where the left lost, why they lost it, where they almost lost, and why they almost lost that.
The left only won nationally because Trump is horrible, and almost lost because the progressives are also horrible. And the progressives are misinterpreting everything and attacking their allies because they have a deep rooted faith in the "future is intersectional" narrative.
Progressives view the destruction of tradition as progress, and view progress as inevitable, and so they don't see how they could possibly be wrong. They forget that the entire tension between progressives and traditionalists is about the relative pace of progress, and whether that progress is happening in a direction that has efficacy.
The left eating itself is going to be the story to watch in the next four years.