The National Catholic Reporter had a recent viewpoint article which captures well a central issue in talking about immigration:
So many Americans are now nearly hysterical about the "immigration problem," suggesting remedies like a high wall along the entire border, stricter enforcement, tougher punishments, and so on. What doesn't seem to be understood is that when your children are dying of malnutrition, when you have no hope of improving the miserable conditions in which you and your family are forced to live, no wall, no amount of enforcement, no punishment will keep you from doing what provides hope.
As well-known as are the problems of Latin America, many Americans fail to see the relationship between those problems and immigration. Yet it seems obvious that if we want to curb immigration, we have to help give people a reason to stay where they are, which is what they want to do. Chronic poverty and other problems among our neighbors in Latin America represent a permanent crisis, for them and ultimately for us. And what we've been doing so far is woefully inadequate to address the problem. Massive U.S. and other First-World aid, perhaps similar to that offered by the Alliance for Progress of the '60s -- aid that gets to the people in the form of education, health care and economic opportunity -- is the only thing that will solve the immigration problem and avoid more violent forms of escape.