I don't think this narrative of an overall rightwards shift in the democratic party is accurate. It's just such a clean narrative and entirely too convenient for their opposition. It also just doesn't match the way their rhetoric has changed over the years. The left flank has at the very least gotten more left, what with the talk of Universal Healthcare and support of Unions that was unthinkable not too long ago.
Tankies and MAGA-types will never acknowledge or are incapable of comprehending that many "opposing" political and economic philosophies (e.g., socialism, communism, capitalism, republicanism, etc.) are all historically liberal philosophies that find their roots in The Enlightenment.
Authoritarians (i.e., tankies, corporatists, theocrats, fascists, statists, totalitarians, and anyone else who says "I'm in charge forever") of every stripe are assholes and should rightly be distrusted, ridiculed, and held in deep contempt by anyone who values free inquiry and thought and the principle of "consent of the governed".
Make sure that the lesser evil doesn't win, that way everyone will know that the locus of power resides in the left, and not the right which just won yet another election!