I believe the below article gives us a sort of sidelong glance at what is actually driving the foot-dragging in the border/illegal immigrant debates.

Reduced Dominance Is Predicted for U.S.

An intelligence forecast being prepared for the next president on future global risks envisions a steady decline in U.S. dominance in the coming decades, as the world is reshaped by globalization, battered by climate change, and destabilized by regional upheavals over shortages of food, water and energy.
But among industrialized states, declining birthrates will create new economic stresses as populations become grayer. In China, Japan and Europe, the ratio of working adults to seniors "begins to approach one to three," he said.

The United States will fare better than many other industrial powers, in part because it is relatively more open to immigration. Newcomers will inject into the U.S. economy a vitality that will be absent in much of Europe and Japan -- countries that are "on a good day, highly chauvinistic," he said.
http://www.washingtonpost.com/wp-dyn/co ... 03302.html

I've long thought the illegal immigration problem to be at its center an economic issue. Our Keynesian economic beliefs require perpetual growth, so that is the idea that must ultimately be attacked. Austrian Economics provides a good rebuttal of many of Keynes economic theories.