If there’s one thing Milton Mayer keeps coming back to, it’s how it was all the fault of the establishment German political parties of the early 1930s for not being more motivating of people to vote for them, and no one on an individual level needs to do anything until they do first. He keeps harping on that central point: If a dangerous political movement arises in your country, it’s okay to hang out and wait and not resist it until the alternative is sufficiently awesome for your tastes. It’s pretty much the central theme of his whole book.
(I mean, honestly, I don’t disagree with you that the general crappiness of most of the Democrats from about 1992 up to and including 2016 laid some abundant groundwork for the rise of Trump. That doesn’t mean it is safe for anyone in the world to let Trump come to power again this year.)