So, RE: A wall preventing immigration
I have never crossed the border into Mexico, but can't anyone who holds a valid passport (generally, I'm sure there are exceptions) come into the United States by car, plane, or whatever? Just book a RT flight to LA, tell the DHS agent that you are here to go to Disney World and have a return flight in a week. Once they are across the border, if they want to find a way to disappear and stay in the country permanently, couldn't they do that just as effectively as anyone who had walked across into the New Mexican desert? What exactly is the wall going to stop?