This is a good article:
“Right-wing populism and left-wing identity politics have risen in tandem since 2013. Why?
The connecting thread is the contradictions of multiculturalism, which encourage a “common enemy” form of minority identity while repressing even moderate expressions of majority identity. The former produces antagonistic identity politics on the left, while both contribute to populist blowback on the right.
In the high culture, the advent of social media helped the cultural Left experience its Third Great Awakening, matching the waves of enthusiasm of the late ’60s and late ’80s. Meanwhile, multiculturalism’s half-century sway has presided over profound ethnic shifts, producing mounting conservative discontent. By narrowing the space for debating immigration, progressive taboos prevented mainstream liberals and conservatives from reaching a settlement on the issue. We are now reaping the results.
Multiculturalism, which originated among small circles of bohemian intellectuals in the 1910s, came to be established in the elite institutions and mass culture of Western societies from the mid-1960s. Once ascendant, these values created new taboos that drew the boundaries of acceptable debate. These frowned on any expression of a national identity in which the ethnic majority was accorded a prominent role. Since slowing the rate of ethnocultural change is a primary motive for restrictionists, and this was viewed as beyond the pale, the desire to reduce immigration was considered racist.
Second, multiculturalism, as its name suggests, encouraged minority groups to celebrate a politicized version of their identity. At multiculturalism’s heart, therefore, lies a contradiction: White majorities are compelled to be cosmopolitan, urged to supersede their ascribed identity. Minorities are enjoined to do the reverse. …”
It is silent on the Jewish role in the rise of multiculturalism.
Eric Kaufmann addresses it though in his book The Rise and Fall of Anglo-America. Jews played a central role in creating a deracinated, cosmopolitan American national identity in the 20th century. They have played an even bigger role in stigmatizing and policing White identity politics.
“In accepting the expanded definition of racism used by the multicultural Left, the political mainstream closed its eyes to popular demands for lower immigration, paving the way for Trump and Brexit. Liberals subsequently mobilized in response to populist extremism, and survey data show increased liberal support for multicultural tenets such as affirmative action and increased immigration. All of this has further fueled polarization and eroded the quality of government.”
If something can’t continue forever, it will stop.
Eventually, the crisis brought on by the cultural polarization will come. The two sides are drifting further and further apart with each election cycle. Just look at the State of the Union last night with AOC or when Bernie Sanders was attacked for delivering his own response.