I am frankly tired of bishops pulling Biblical texts out of context to make a politically correct point.  The illegal immigrant of today is not the Abraham of Genesis, where neither Ur nor Canaan had borders, visas, or immigration control.  Bishops would do better to recognize that the Church has always recognized the right of sovereign states to control their borders.  Rather than pretend the illegal immigrant is a wandering Aramean, they might focus on the jobs lost by their own American flocks because they are taken by immigrants, the danger faced by their own American flocks when dealing with illegal and criminal activities of aliens, and the obligation of Mexico to provide a decent living for its own people rather than sloughing them off to the gringoes north of the border.