A sovereign nation and its people have a choice in terms of who comes in to their country. It can bring in a small or large number of immigrants. Likewise, it can bring in immigrants who are similar to those already in the country, or it can bring in people who are different. The approach in the United States over the past few decades is to bring in a large number of immigrants who are very different. For most of our history, immigrants were brought in to assimilate and contribute to American society. The country's founders were European, so thus most immigrants were European. The country's founders were Christian, so thus most immigrants were Christian. Immigrants were expected to contribute, not be on welfare, embody the American dream, adopt American customs, speak English, and raise their children as Americans.
There have certainly been serious strains along the way. Allowing millions of Italians, Eastern European, and Jewish immigrants to crowd a handful of cities (leading to tenements, low wages, and poor conditions) was not a sustainable approach - the 1924 Immigration Act sharply restricted new arrivals, and many earlier immigrants and their descendants assimilated over subsequent generations.
We are in a similar but more dire situation today. We have had decades of mass immigration with little assimilation. We have allowed millions of people in without making assimilation a clear priority of immigration policy. In order to have sustainable immigration, we need to abide by three principles:
