Stepped-up border enforcement appears to be having some impact, shutting down traditional mom-and-pop people smuggling efforts and driving more clients to larger, more professionalized organized crime operations often involved in the drug smuggling business. And so it goes. I wouldn't say cracking down on illegal immigration is a huge priority for me, but by any standard border enforcement is a relatively ineffective way to go about it. Well-designed systems to make it harder for illegals to get jobs and rent houses would make coming to the United States illegally much less attractive. The strong incentives to cross the border, rather than the physical feasibility of doing it, is why so many people cross.
Matthew Yglesias is a former writer and editor at The Atlantic.