And, as with all unlawful activities, society must accept that it will be impossible to eliminate all illegal immigration. Much can be done, but after a certain point the law of diminishing returns sets in. Government could reduce illegal drug use more substantially with a much greater investment of funds, but this would require diverting money from other priorities. It also could take actions like universal random drug testing, but this would put a burden on all citizens and infringe on their civil liberties. Any effort to combat illegal immigration faces the same limitations.
Legal immigration requires a completely different outlook and set of tools.
It more nearly resembles a regulatory activity, like the management of national forests or control of the money supply. The goal is to direct the use of an important resource, legal immigrants, in a way that serves the interests of our nation and that provides the greatest benefits possible for both the immigrants and the society that receives them. Illegal immigration requires policies that are clear, sharp, and statutory, and a willingness to deal with the dangers of unintended consequences. Legal immigration requires policies that are flexible and dynamic, and a willingness to cope with the difficulties of trying to mold a huge demographic event to conform with national interests. As different as they are, these two realms of immigration policy must be coordinated not only with each other but also with polices in seemingly unrelated areas that are deeply affected by immigration.