Honestly, this is the absolute least we can do. This is a wealthy and relatively safe and stable country with lots of opportunity. Lots and lots of people want to come here, for survival, freedom, or just for a better life. You know, like most of our own ancestors (apart from those who were brought here by force). The best thing about America is it keeps getting remade by each successive generation of immigrants. The culture is incomparably richer for it.