The "reverse migration" of illegal immigrants has already begun.
I was advocating this "solution by attrition" over at Daily Whackjob in a heated discussion I was having with others over illegal immigration. I stated that if you take away the jobs/handouts available to illegal immigrants, and that if you make them believe that we're going to actually get serious as a nation on immigration control, they'll start to leave on their own.
Now, the article admits that part of the reason is the slowdown of economic growth has some illegals worried that the number of jobs available are going to shrink. This, combined with states cracking down on employers of illegal aliens, does not make many places that were once safe havens for illegal immigrants very appealling anymore.
Want to know who else has stated this theory as part of the solution to the illegal immigrant problem? Fred Thompson, of course.