The origins of liberal progressivism

According to Kaufmann's The Rise and Fall of Anglo-America:

Adler's realist logic brusquely exposed the tension between Reform Judaism's manifest universalism and its latent ethnicism. Under his influence, Anglo-Protestant thinkers would turn the same cast-iron logic toward their own group and call for its termination as forthrightly as Adler did for the Jews. Adler's message is significant because it not longer sought to prepare Jews for assimilation into their host society but rather urged them to embrace a universalist, post-ethnic Utopia. [. . .] With time, and with the ideological aid of another Reformed Jew--albeit strongly Zionist--Israel Zangwill, Anglo-Protestant intellectuals would adapt the new variant of Adler's ideas to their own situation. [p. 92]

Incidentally, Adler claimed Jews would spontaneously "universalize themselves out of existence" only after they completed a "messianic mission [. . .] to spread monotheism around the world and unite all people under God".

Prior to the 1890s, the universalistic radical potential within Progressivism lay hidden within its "left-conservative" intellectual matrix. However, the best educated, most critical minds within Progressivism were beginning to form a vision of their society that embraced universalistic left-liberalism, or "liberal" Progressivism. Once again, Felix Adler and the Ethical Culture Society appear to have been the innovators of the Liberal-Progressive approach. [pp. 94-95]