Yeah, they even have a state called California which gets quite a few people from Mexico coming in across the border. Many of them speak little or no English. I hear it is doing okay.
If we do too good of a job of keeping out Mexicans, we will have serious food shortages. There will also be other areas that suffer -- like upscale landscaping that seems to be mostly maintained by Mexican workers -- but the whole food shortage thing worries me lots more.
So, I hope we don't get too clever about it.
A wall all along the US/Mexico border is a fantasy. It's the grown up equivalent of promising to put soda in the drinking fountains when running for class president.