While environmental concerns are certainly serious and warrant consideration, we need to balance the competing interests here. It is only a handful of species that would be threatened by this project, and any such endangered species can be moved into specially-designed preservation facilities that mimic the natural habitat. On the other hand, there is no other truly effective way to stop illegal immigrant crossings. In this sense, the local environment is a sacrifice of necessity. A related environmental concern is the pollution border-crossers leave in the desert and surrounding habitats, which would actually be reduced if fewer of them were crossing.