… you can forget about Mexico. From a correspondent:

The Mexicans seem to be assuming that if we have a guest worker program, it will be conducted for their benefit. Actually, we would be far better off with guest workers from China, India and southeast Asia. They will work for less, as the Mexican maquiladora experience has shown. When sent back home at the end of their period of indentured servitude, they will be much less likely to return on their own, given the intervening Pacific Ocean. And they will have no irredentist ideas to cloud their thinking.