As the birth rate of USA citizenry drops well below the replacement level and our population level yet continues to dramatically increase, it is obvious that immigrants are the wave of the future. As global warming increases, the displacement of more and more equatorial populations will increase the pressures on our borders. And as temperatures in the USA increase and air conditioning costs increase (economic and environmental), those naturally better adapted to such conditions are these new arrivals.
If you want to see what how even a seemingly impenetrable border fence cannot stop large groups of desperate people, then watch the first half of the following YouTube video.
“Europe’s most fortified border is in Africa” (11 minutes)