Whenever there is a disconnect between the law and reality, reality finds ways of making the law irrelevant...
It is always hard to oppose an emotional reaction with logical arguments and statistical evidence. Otherwise, the argument for the decriminalization of immigrants and a policy that helped match future demand for migrant workers with future supply would have been won long ago.
There is a legitimate debate over how open America's borders should be. But that debate today is far too soiled by those persons who think that merely calling "illegal" immigrants "criminals" settles the matter. It does not. "Illegal" immigrants are "criminals" only because government policy declares them to be -- in the same way that persons openly practicing Christianity or Judaism in Soviet Russia were "criminals" only because government policy declared them to be. The contours and specifics of this policy are precisely what is at issue in the debate over how widely open U.S. borders ought to be. This debate should be on the economics and the national-security issues raised by immigration; it should not be confused by the confusing (and often self-serving) application of the term "criminal" to persons who come to America without Uncle Sam's permission -- permission that is very difficult to get.
Read Don's whole post. He says, using a lot of Latin terminology, that murder would be wrong even if it were not illegal. However, crossing a border to find a job is not wrong purely by government fiat.
Also, Dani Rodrick points to an analysis that quantifies my co-blogger's argument that you really have to think that native-born workers are some sort of moral master race in order to justify bias against immigrants.
I think we ought to ration work visas by price instead of by quantity. That is, the government should charge people who want to work here a fee of, say, $1000 a year. People who are anti-immigrant could argue for higher fees. Those of us who are pro-immigrant might argue for lower fees. But either way, it would be a more credible and a more reasonable policy than what we have now or what is being proposed in Congress.