I say lets do it ....let Mexico into the Union!
once again, mexicans in no way whatsoever want to be part of the usa. ask some of them and find out for yourself.
Clean it up, Divide it into separate states (already is), bring in each one at a time as they get their act together, Refute all previous Mexican national laws in order to come in, Investments and building of their separate economies will sky rocket as money flows into the new states. Immigration "problems" will be going in the opposite direction........