WHAT IF there was a terrible disease South of the border, and immigrants would bring it into the USA? Would we THEN try to keep them out? Or test everyone entering, to make sure that person was not a carrier? If we let everyone in - seeking treatment - our hospital system would quickly be overwhelmed.
I think most citizens and even people already immigrated without papers, would be in favor of closing the border TIGHT.
So what type of problem (or types of problems) would justify limits on immigration?
need for more money for welfare/food stamps, need for more social services, need for more teachers, need for more hospitals, need for more law enforcement officers, possible terrorists entering, competition for employment, overcrowding, overuse of resources, etc. etc.
And what reasons would justify allowing more immigration?
unlimited family unification, enrich our culture, rescue from violence or oppression, need for workers in certain industries, poverty in country of origin