Take It To The Border
I am no expert in these matters, but it strikes me that the construction and policing along the Mexican border must cost the US more than they stand to lose from allowing 'aliens' into a land that was theirs in the first place. It has already been well documented that the US labor market requires immigrants to keep functioning and I believe that the border restrictions and this ridiculous fence serve only to appease right wing voters.
Call me an idealist, even call me an anarchist, but I believe in one world and view all borders as nonsense.