My present purpose, however, is intellectual. In the debate about population and immigration, the adversaries tend to talk past each other, because the concept of the national good is simply absent from the thinking particularly of immigration advocates. They dismiss the argument as racism or xenophobia. Only if you believe that the social good is important and worth the sacrifice of some immediate individual benefits does the argument even reach you. In a society where the social good is seldom invoked except as a cover for parochial interest, it simply sounds irrelevant.
Individual interest is concentrated.
The social interest is dilute. Moreover, there is a conflict of moral values involved here. The two World Wars resulted in part from the excesses of nationalism, and the word has become pejorative in many minds. The result is that arguments based on the national good are suspect. It is easy to associate that state of mind with liberals, who tend to be Democrats.