[sevenless]

The nation-state is founded on the ideal of a sovereign state for a specific ethno-cultural group, and immigration fundamentally contradicts this. However, that is not a reason to oppose immigration. Mass immigration in sufficient volume will ultimately destroy the national culture. However, that culture has no inherent existence rights, not should the world be so arranged to preserve national cultures.

Consider, too, that a wealthy democracy could simply refuse to help a poor neighboring nation, and let them all starve to death. That would be unjust, even though it would be perfectly democratic. This indicates that there is a fundamental problem with democracy; democracy is wrong. The flaw is not hard to find: the people most affected by the democratic decision are not those who get to make the decision. The basic problem of democracy is how the demos is defined.

It is very probable that many people have xenophobic and racist instincts. Racism may be biologically ingrained. Probably 10-20% of people would like all immigrants deported. They will never be happy as long as they are not living in an ethnically 'pure' state. That is a good reason for not allowing those views any political representation. We should exclude immigration from being a legitimate democratic issue, because democratic votes on migration always turn into racist populism. Just like we shouldn't put minority rights to a vote, neither should immigration be put to a vote.

Yes, immigration disrupts the way people live, but so does (for example) industrialization. The interests of the indigenous population and immigrants do conflict. But there is still no ethical reason to stop people moving to improve their lives, to limit immigration, or to confer migration veto rights on their present of former inhabitants.