The whole wall thing was BS to play to the crowds. The US-Mexico border is almost 2,000 miles long. Look at it on Google Earth. How the hell are you going to build a giant wall across all those deep canyons and rivers and deserts? And even if you did, at a cost of a couple of trillion dollars, they'd just tunnel under it or climb over it with big ladders or blow holes in it or come in on boats like they are doing to Europe (and, speaking of that, if I was in charge and a Spanish or Italian "rescue ship" rescued boats full of black Africans at sea, like they keep doing, and brought them to Spain or Italy, I'd have the captain of the rescue ship shot for treason and lock up the crew). And telling Mexicans that they will pay for it was BS too. All that accomplished was to infuriate even the best of them, what with their machismo and all. Big walls in and around the cities like Juarez and Nogales and Tijuana makes sense, but they already have walls there and they tunnel under them. You just make strong laws and strictly enforce them and quit futzing around at the border. Give the border patrol orders to shoot to kill. Make forced labor camps for illegal immigrants. They don't talk about it much, and they kept it secret for many years, and they still do to the full extent of it, but that's how they built over 9,000 foot high Mt. Lemmon highway in Tucson Arizona, with slave labor - interned Japanese Americans, German POW's, and illegal immigrants from Mexico.