Libertarian purists (e.g., Donald Boudreaux and Bryan Caplan) like to criticize the critics of illegal immigration. In the minds of libertarian purists, national borders are merely statist concoctions. It is anathema to them that the United States exists primarily for the purpose of protecting its citizens and their liberty rights. (Well, it did exist for that purpose originally and for a long time, and it still does to some extent.) Libertarian purists seem to believe that, somehow, defense would be unnecessary and rights would be enforced even if the United States did not exist as a coherent, delimited entity. Good luck with that!
In any event, libertarian purists like to criticize those critics of illegal immigration who claim that (1) the lure of welfare benefits draws illegal immigrants and (2) illegal immigrants add to the burden on tax-paying Americans. My research into those issues may be out of date, so I might decide to update my old findings (contrary to an earlier suggestion that I would drop the subject). For the time being, I am content to note the following:
More to come, perhaps.