1. Perhaps the central plank of the Trump campaign is that our open border policy is turning America into a Third World country. There's some truth to that, but it's a very indiscriminate way of casting the issue. There are roughly two different models regarding immigration policy: multiculturalism and assimilation.
2. Multiculturalism
In theory, multiculturalism is a policy for protecting and preserving cultural diversity, with a focus on accommodating minorities. Multiculturalism goes hand-in-hand with identity politics. In this paradigm, people have special rights conferred by membership in a given group. The social ontology is communitarian rather than individualistic.
In reality, multiculturalism is anti-Christian, anti-white, anti-male, anti-heteronormative, anti-Western civilization. Certain "protected classes" are singled out for special treatment, viz. Muslims, women, homosexuals, transgendered, blacks, Latinos.
There are some basic tensions in multiculturalism. It's a euphemism for a discriminatory agenda. In practice, multiculturalism is generally hostile to cultural diversity inasmuch as most cultures are traditionally patriarchal, religious, gender binary, and heteronormative. Likewise, most cultures traditionally espouse human exceptionalism (in contrast to animal rights).
In practice, multiculturalists begin with their ideological priorities and preferences, then define multiculturalism to mirror their ideological priorities and preferences. In case of conflict, Muslim rights trump women's rights, homosexual/transgender rights trump black rights, &c.
Toleration of cultural groups sanctions intolerance within cultural groups. In-group hierarchies. Internal discrimination against vulnerable members of the group. Protecting minority group rights at the expense of disadvantaged individuals who may be minorities in contrast to the group. That's because the majority/minority distinction operates at different scales.
The collective orientation tramples on individual rights. Tramples on free association. The right to leave your hereditary social group or join a new social group.
3. Assimilation
According to the melting pot paradigm, immigrants should assimilate to the dominant, majority culture. Learn the official language. Everyone should have the same general human rights and civil rights.
4. Ironically, both assimilationist and multiculturalist models use culture as the benchmark, but culture is inherently fluid. Immigration itself is a catalyst for cultural change. Likewise, you have internal cultural evolution, even in fairly homogenous societies. For instance, there's great cultural diversity within Islam. Multiculturalism codifies ethnic stereotypes.
When they have the freedom to do so, individuals frequently mix-and-match different cultural options. Likewise, what about members of different ethnic groups who belong to the same socioeconomic class? Identity politics is in tension with cross-cultural commonalities (e.g. social class).
Sometimes assimilation goes in the opposite direction. For instance, some caucasians become fascinated by Chinese civilization. They study it. Immerse themselves in Chinese culture. Essentially adopt Chinese culture.
4. Cultural integration
In what sense are our current immigration policies turning the nation into a Third World country? That charge could mean the combination of virtually unrestricted immigration with the welfare state is dragging the country down to the economic level of many Third World countries. It could also mean introducing ideological values that are alien to our system of government, viz. sharia.
In two qualified respects, assimilation is good:
i) Political assimilation
Immigrants should assimilate to our political system, viz. limited government, consent of the governed, the Bill of Rights. Indeed, it's pointless for immigrations to come here in order to escape the conditions they left behind if they were going to transplant the same dysfunctional values into American soil. Islam is the best example.
ii) Christian assimilation
Ideally, immigrants should assimilate to Christianity. That provides a common basis for social ethics and public policy. Of course, that can't be imposed–only encouraged.
Apart from those two examples, I don't see any particular value in cultural assimilation. Within those two parameters, I like cultural diversity. Much would be lost in the melting pot if we blended everybody into the dominant cultural fondue. By that I don't mean cultural blending is wrong; rather, it's wrong as a matter of policy.
To take one example, it's interesting to observe the synergism between ethnicity and Christianity. How ethnic groups who've been evangelized adapt their culture to Christian norms. Each is Christian in a different way, as the Gospel is cross-contextualized. If people are properly discipled, their culture will take care of itself.
To take another example, when I watch contemporary English movies and TV dramas, I notice that black English actors have assimilated to the accent and affect of white English actors. I think that's unfortunate.
It's striking to contrast that with black Americans, who've retained a distinctive subculture. I think that's worthwhile. That's a cultural good. Biracial, South African comedian Trevor Noah does an amusing, but admiring impersonation of black Americans.
