Jed Esty in The Baffler:
In the United States, the political baptism of the non-elites to the hegemonic mission happened in the years between 1920 and 1960. Mass culture in those crucial years paved the way for a patriotic politics built around U.S. military prowess, massive expansion of literacy and lifestyle, the phobias of the Red Scare and Jim Crow, and commercial success across the globe. By the midcentury, anti-communism produced a coordinated ideological effort at cohesion. Elites recruited the political aspirations of working-class and middle-class voters into the cause of American supremacy, framing the export of American consumer capitalism as the triple gift of sacred freedom, true democracy, and general prosperity. The Hollywood studio system picked up the plots of late-Victorian adventure genres, adapting them to the worldview of U.S. supremacy and global centrality.
More here.