An especially clever argument by Nathan Smith:

[G]lobalization has half-Americanized half the world already. 19th-century immigrants may have been racially more
similar to America’s white native majority, but they were less familiar
with democracy, with the English language, with America via movies and
music and TV, with American-style market capitalism, with Coke and
McDonalds and Microsoft and Google and many other American firms, with
blue jeans and free speech and religious tolerance, than a 19th-century
immigrant from the Hapbsurg empire or tsarist Russia. There are lots and
lots of foreigners who could show up on an American college campus or
in an American corporate office building and fit in, just fine, almost
immediately. There’s no reason to think that 15% or so was ever an upper
bound on the foreign-born share of the population that America could
absorb, and that upper bound is probably much higher today, because of
cultural assimilation that has occurs across international borders, with
the influences running both from abroad to America and from America to
abroad, though the latter direction of influence is surely more

In short, the marriage of modern technology and Western culture has covertly pre-assimilated hundreds of millions of “foreigners” around the globe.