This is well stated. Add to it the very real electoral structural disadvantages the Dem party is facing (sheer number of red states; red congressional districts) plus the disenfranchisement of traditional Dem voting blocs because of this splintering you’re talking about and what you have is a good, old-fashioned crack up.
However, I’ll suggest that both parties, and their relevant ideological bases, are fraying because of a mass personalization in our culture and the growing irrelevance of our governments at all levels.
Kiss the two party system Goodbye.
Thanks for your post!