That quote, attributed Jeffrey Escofier, is very interesting.
Nationalism of the "modern" philosophies of the 20th century attempted to define nationalism away from ethnic identity, and toward shared ideals such as democracy, freedom, and equality. It is interesting to note that liberalism and communism both attempted to do this (though obviously fascism and Nazism took the opposite tack).
The post-modern era is seeing a back-sliding to the more tribal pursuit of ethnic identity, away from the "modern" ideals that inspired the UU Seven Principles.
Philosopher Ken Wilber has a very interesting narrative of this historical development, in his book Trump and a Post-Truth World.
Have you by chance read Ken Wilber's - Trump and a Post Truth World?