Deport them all to Syria. As an excuse you can say they have to be Syrian because they don’t have a Mexican passport so they must have come over from Syria.
"What? What? No passport? This must be another Syrian. Stuff him on the airplane! What? He speaks Spanish? You don't say! I hear there's lots of Spanish speaking Syrians. Put him on the plane."
I figure that it will only take a plane or two full of deportees to cause a stampede of epic proportions back to south of the border. The problem will take care of itself.
To find out why the blog is pink just cut and paste this: http://piccoloshash.blogspot.com/2009/12/my-feminine-side-blog-stays-pink.html NO ANIMALS WERE HARMED IN THE WRITING OF TODAY'S ESSAY