I've been wondering for some time now whether it is possible to be against immigration without being xenophobic. In fact, I have been thinking about the possibility of a moral argument in favor of stronger enforcement and returning Mexican citizens to Mexico. I belive I have the beginnings of such an argument.
As bad as the differences are between the haves and the have-nots in America, as corrupt and unresponsive as politics are in America, things are worse in Latin America. When there is widespread exploitation of the poor and corruption, people suffer. I belive these two statements are incontrovertable.
Now, how can we make things better in Latin America? From the outside (as Norteamericanos), there isn't much of anything we can do. Aid (military and economic) tends to be diverted to serve the interests of a small ruling class. I believe that most of us would accept that statement, too.
Now for the more controversial premises.
Change in a culture is brought about by a minority of people, who are more talented (in a very broad sense) than most people in that society. There are people born into the poorest of families who have great ability.
These people can do one of two things: they can work for change at home (start businesses, become medical professionals, and so forth), or they can leave for another country where they have a much better chance of success. The best chance for these countries to become first world economies that respect the civil rights of their citizens is for the most talented citizens in those countries to work, in those countries, for revolution (again, defined in a very broad sense). This assumes that the economic effect of the remittances that are being sent from the United States back to Latin America is neutral -- I remember seeing a good piece about this in the New York Times Sunday Section a few weeks back.
Ethically, we are concerned about ALL of the people in Latin American countries, not just those who have superior abilities who are now coming here.
Therefore, there is an ethical argument for more restriction on immigration and returning people (who will NOT settle anymore for the way things have always been) to there native countries. One need not be a xenophobe to support such a plan.