Between 1905 and 1913 the Protestant church establishment (functionaries within the Protestant churches) broke from the earlier view; they now supported the idea of pluralism in which no single group would be dominant. Shortly after, the Greenwich Village intellectuals also shifted to a pluralist and cosmopolitan position. Randolph Bourne wrote a significant essay in 1916 in which he claimed that Anglo-America had no vital culture of its own and that therefore it was best for Anglo-Americans to become cosmopolitan consumers of the more authentic cultures of others.
What happened next? According to Kaufmann the loss of the intellectual class continued apace. Kaufmann observes of the period following WWI:
For the first time in its history, a considerable number of Anglo-American intellectuals openly disparaged the traditions of their own ethnic group.
He gives as an example the novel Main Street (1920) by Sinclair Lewis in which the Anglo townsfolk are described as "a savourless people, gulping tasteless food," the protagonist, Carol Kennicott, finds welcome novelty in the Scandinavian population of the town, but is disappointed when she observes them being "Americanized into uniformity...and along with these foreigners she felt herself being ironed into glossy mediocrity".
This is clearly a reaction against the earlier view: Anglo-Saxons are no longer bearers of a special dispensation, but represent a cultureless mediocrity. A multiculture, in this scenario, becomes a form of welcome relief from Anglo conformism and assimilation is to be regretted.
In the 1930s, a new generation of New York intellectuals emerged to carry on the cosmopolitan attitudes of the pre-WWI avant-garde. This generation had a higher representation of Jewish intellectuals; Kaufmann considers it to be a roughly equal fusion of Jewish and Anglo-Saxon radicals.
According to historian Terry Cooney, these intellectuals thought of themselves as standing for "cosmopolitanism, internationalism, secularism, rationalism, urban complexity, intellectual sophistication, artistic creativity, and progress" as opposed to the alternative of "ethnic and regional particularism, nationalism, religious mystification, emotionalism, rural narrowness, simplification, populist politics, popular writing, artistic stagnation, and reaction."
It was in the interwar period also that an artistic clash occurred. An artistic movement called Regionalism represented a popular, national view:
This school of art and literature, known as Regionalism, sought to draw on the American landscape, its history and folk culture, in an attempt to generate an authentically native "American" culture and reconstruct an American sense of national community.
The Regionalists were attacked by the avant-garde intellectuals as reactionary populists. Mary McCarthy, for instance, complained that Regionalist Maxwell Anderson's success came from an appeal to "old-fashioned American symbols" and Meyer Schapiro warned that "The appeal to national sentiment should set us on guard" and then criticised Thomas Hart Benton's
conceited anti-intellectualism, hatred of the foreign, his emphasis on the strong and masculine, his uncritical and unhistorical elevation of the folk, his antagonism to the cities, his ignorant and violent remarks on radicalism
By the end of WWII regionalism had given way to an abstract expressionism that was more in line with the views of the intellectual avant-garde. It was at this time, too, that the avant-garde and the American government moved more closely together. The New York intellectuals had abandoned Soviet communism and they looked to America as the focus for their liberal cosmopolitanism; the American government came at the same time to look to the avant-garde intellectuals as a bulwark against communism.
So by 1950 the older tradition had been destroyed amongst the intellectual and artistic elite, who were dedicated to liberal cosmopolitanism, and this elite had the support of those wielding political power. That's not quite the end of the story: Kaufmann goes on to look at how the avant-garde then won support in the institutions and, following from that, how rank and file opinion was won over.
One thing to remember in all this: the avant-garde intellectuals were reacting against an older understanding that had its own limitations. What was really needed was something different to both.