At some point we have to confront where this "there's no race except the human race" and "no human is illegal" ideology is coming from: Christianity
The nationalist view says: every people has the right to define its own membership and preserve its majority
The Christian universalist view (applied to immigration and citizenship) says: Every person has the right to enter, be born into, and claim membership in any nation, with no regard for preserving any kind of majority.
One prioritizes the collective right of a specific people to maintain their homeland, culture and demographic continuity. The other prioritizes the individual "human dignity" of the stranger, turning nations into hotels with no checkout policy