I think the good news is the employees of the Baja Ca sand and gravel pits are not illegal aliens.
I would propose getting a lot of sand and gravel by digging a moat along the southern border of the US. Really deep. With a strong fence, for the sake of safety at the northern edge.
Good idea, but the environmentalists would never allow that.
The mere suggestion of this, though, proves that the Bush Administration is in bed with Big Gravel.