immigration was unplanned, but supported by government
The U.S. is a rather unique case. We are literally a nation of immigrants. In the beginning, all were welcome because we needed these people to build the nation. When my great great paternal grandfather immigrated from Swabia 1848, this was still the case. However, by 1906, when my maternal grandparents immigrated, the borders were already beginning to close. The nation was becoming more selective, and in the 1920s this selectivity was enforced by discriminatory immigration laws.
I think the evolution of immigration policy demonstrates a basic principal: immigrants are not introduced into a neutral environment. There is a resident population that figures in the equation. That was the mistake of the Europeans when they didn't regulate (plan) immigration. That's the problem in the U.S. as my country wrestles with immigration as a political and social issue.
We need immigrants. A lot of people don't realize that. We would have zero or minimal population growth without immigration. The implications of that are dire. What we need is a rational immigration policy, such as the one you describe in Switzerland. Immigration to the US has been so uncontrolled, even chaotic, that anti-immigration sentiment runs high. We are indeed in the midst of an immigration crisis.
Now we not only have to figure out how to manage immigration so that it benefits us, but we also have to figure out how to sell a rational immigration policy to a lot of voters.