I think that wall is just a warning for the ilegal inmigrant inside US, its just a expression to caused fear and sop the huge amount of ilegal mexicans into the border.
The flow of illegal Mexicans must be stopped. They are not paying the taxes, and they are exploiting the welfare system by claiming child benefits for their dozens of children. Cheap labor is good, as long as they are legal.
How do you get welfare benefits, or any social welfare, without a valid and unique SSN? Employers can collect taxes from them, and they can pay into social security because the government rarely questions when you give it money. E-verify isn't that sophisticated apparently (which is a while different issue). But even with perfectly good faked papers (a perfect copy of a legitimate persons identity), how do you claim benefits when you have to apply, in person, with a case worker? You would need to supply pay stubs, all types of shit, too much info for a non person to generate. If they can, they probably have enough resources not to want to go on record as being in the country, given that they are here illegally. Kinda like signing up for DirectTv as a fugitive.
And did you know that White America makes up the majority of social welfare recipients? It's kinda duh, given the overwhelming majority of America is white, but it's a talking point that may have gotten lost on Breitbart. Because we all know colored people use all the food stamps, and do all the crime.
I finally get it! Does Make America Great Again actually mean " Please get these fuckin darkies out?"