Mark’s points about the relationship between American dynamism and immigration are well-taken. Again, I’d like to stress that I’m endorsing an exceedingly mild form restrictionism – perhaps a system that expands immigration quotas for Third World countries not adjacent to our border while limiting the number of new arrivals from Latin America. That said, I think Mark dramatically understates the importance (and fragility) of certain “core American values” (for lack of a less Gingrichian phrase).
The genius of American assimilation is that we’re very good at absorbing and commercializing immigrant cultures’ cosmetic features – witness our shared affection for bastardized Chinese cuisine, Henna tattoos, and globe-trotting pop stars. Among other things, this has the effect of making the United States open and welcoming to newcomers without dramatically altering our most important features. I don’t doubt that there have been dramatic changes in popular culture throughout American history, but I like to think there’s a certain permanence (or at least continuity) among the cultural and social norms that make the United States tick.
What are “core American values?” At the risk of sounding like the “Issues” page on Gingrich2012.com (G-d save us), I think we can tentatively identify certain consistent features that undergird the United States’ success: An entrepreneurial bent, a faith in hard work and meritocracy, a high level of social trust that encourages cohesion, charity, and reasonably efficient government, robust patriotism, and an enduring belief in liberty, equality, and opportunity.
I happen to think that nearly every human being on the planet is born with the faculties to comprehend and embrace this (admittedly ill-defined) value system. But these norms are learned, not innate, and I also think it’s exceedingly naive to assume they’re as easily transmissible as a taste for American popular culture.
One final point: Mark expresses some skepticism of the idea that American values aren’t easily adopted. Conclusive evidence is hard to come by for this sort of thing, but I’ve always thought that the relative absence of liberal democratic capitalism outside the Euro-American core is a telling indicator of how difficult it is for non-Westerners to adopt Western values.