If We Assist Illegal Immigrants, Should We Assist Illegal Immigration?

Joe Knippenberg, in addition to citing an interesting letter sent by House GOP leaders to the U.S. Conference of Catholic Bishops insisting that the immigration bill has been misconstrued, responds to criticism of his earlier comments on Cardinal Mahony:

I probably should have softened the language a bit, arguing that the threat of civil disobedience runs the risk of turning natural law into a cover for all sorts of defiance of positive law. I stand behind the thrust of my analysis and would continue to raise the following question. Does Cardinal Mahony think it should be a crime actually to assist people to cross the border illegally, regardless of one’s motives in so doing? It’s one thing to help out immigrants, no questions asked, who present themselves at your doorstep. It’s another altogether to help them into the country.

This is an intriguing question, and perhaps other MoJ-ers have pondered this already.  Certainly the Church recognizes a nation's legitimate interest in maintaining its borders, but under what circumstances would the Church call to help others enter a country illegally?  I assume that there are such circumstances, but that they would not be common.  The immigrant's needs, the situation in the country of origin in relation to those needs, and the stated rationale for the new country's legal exclusion of the immigrant would all be important factors.  In the end, the question will be, what degree of deference do we owe to a nation's own weighing of these factors in crafting their immigration and asylum laws?  How unjust must the laws be before their violation is morally warranted or compelled, and what level of injustice must be present in a particular case to justify defiance of laws that function well overall?   

Rob