There should be (more?) free trade and manufacturing zones established along the US-Mexican Border.
Mexicans and other nationals should be allowed to work at their own national minimum wages and benefit rates or better as the market demands.
We could be exporting the product to other countries. USA capital and competitive labor rates. I bought a toilet made in China a few years ago -- the shipping and breakage costs must be high. If that same toilet was made in one of these free trade and manufacturing zones the profit would go to a USA business and both US persons as well as Mexican and other nationals would have steady work and could live in Mexico near the border.
If the current immigration laws were better enforced against the employers that would help some. But the unreported and untaxed cash economy is maybe 25%? So, deporting illegal immigrants, with what due process the immigration laws require, is necessary. However, a part of the tax on unreported income should be collected with a Federal Sales Tax of 5%. The states can collect it for the federal government and take a 1% fee to use toward the expense of collection and remittance and other state governance costs. The problem is bigger than illegals working on the cheap for cash
This is better than a brain dead solution of capture and deport the Mexicans. That solves nothing because if there is work for them when they sneak back in we will just go in circles.