I think it may be worth a few minutes (but no more) to address the argument against more restrictive immigration which says that “X is a nation of immigrants.”
I say “X” because this argument is no longer limited to the United States: people are now speaking of Sweden, France, Britain, and Germany in the same way. Nor should the argument be limited to America. After all, all people arrived at their present location after moving there (even populations in ancient centers of human life, such as the fertile crescent, moved around a little).
This pseudo-argument is little more than a word game. It replaces the specific with the general. Not all immigrants are of the same kind. Why not a “nation of immigrants from Y“? Populations travel and live together, and replacing the specific with the general results in a true statement — yes, technically they are immigrants — but with less precision, and a false implication: that all one needs to be a member of nation-X is to be an immigrant.
Imagine if we were to say “America is a nation of mammals.” Technically, this is true, but useless. In fact, worse than useless: it may confuse people into believing that gorillas, bears, squirrels, and the ultimate internationalists — whales — might be American. After all, they are mammals. Some are even immigrants.
(Is the Himalayan blackberry “American?”)
Replacing a specific truth with a more general truth in order to justify an untruth is not valid. It is not even philosophy, but sophistry. It is dishonest, it is stupid, and it warrants no more attention.