Victor Davis Hanson is the best writer on the subject.
In the end what is multiculturalism? A global neurosis. For its elite architects, it is a psychological tic, whose loud professions square the circle of enjoying guilt-free the material comfort that only the West can provide. For the rest, multiculturalism is a sort of fraud, a mechanism to blame something that one secretly desires in lieu of addressing the causes of personal or collective self-induced misery.