  Finally, even if each of these moral challenges could also be conclusively answered, this approach would not justify excluding all outsiders. At most, it could explain only why countries would be entitled to limit the flow of culturally distinct immigrants. To put this point in terms of the United States, for instance, even if the aim of preserving American culture would justify placing limits on Mexican immigration, it would not seem to justify excluding all Mexicans, let alone all Canadians.