Since a love of one's own nation is a natural human trait, Americans cannot be expected to become anti-American until they have replaced America as their "motherland" with another one (Africa, the gay "nation," etc.). Therefore the patriotism instinct actually remains intact, since the patriotism of such groups is transferred from America to some other place or identity (which is adhered to with every bit as much "simple-minded jingoism" as any American patriot could possibly manage).
In essence the Left encourages "right wing extremism" among the "oppressed," but this is seldom commented upon even by the Left's most articulate critics.
You make some excellent points, particularly as they describe the move from "God and Country" to a more "acceptable" Balkanization. The concept of divide and conquer was not lost on the marxists.