[A]ll the problems we associate with immigration stem not from the presence of people but from the institutional arrangements in which people interact. Immigration of some types forces on the domestic population new requirements for public infrastructure. Schools must be built and funded, and new public-sector employees hired. The demands on the public purse grow.
New immigrants can receive public assistance. They coalesce based on language and ethnicity and gain control of local governments, through which they then coerce others. They have national voting interests, and their votes are up for grabs by parties representing special interests, which means both parties.
Whereas people will suffer through incredible abuses when imposed by people who share their nationality, they will not tolerate the same from those whom they regard as alien.
The result is social and political upheaval. And what is the source? Not capitalism. Not immigration as such. Rather the core problem is the state, which enables some people to rob others on their own behalf. All other concerns are a distraction from the key issue. The best immigration reform is one that would provide neither impediments toward work for anyone nor subsidies of any sort.
Eliminating the subsidies alone would also help alleviate the resentment that comes with immigration. It would also stop the subsidies that cause people to immigrate for the wrong reasons. In any case, it is pointless and dangerous to pursue the method of using government power to round up illegals and throw them out — a power that is used to the detriment of commercial freedom — when the law still encourages demographic upheaval through subsidies and special rights.
There's a lot more in that article [have another link], he starts out talking about overpopulation and dovetails into immigration and other issues.