Just my 2 cents, and I don't live in a border state. I believe our borders need to be as secure as possible and have some means to validate and document all crossings. I do not understand how we got where we are, but I do attribute capitalism playing a large part. This was pretty much the only source of labor for many farmers, not to mention other labor intensive work performed under undesirable conditions.
From my limited experience with South American emigrants, they have been courteous, dependable, hard workers and honest. For the ones I have seen, I hope that they can be treated with some respect to resolve a difficult situation