The current number of illegals generally quoted is bogus. It's closer to 20 or 24 million, with more pouring in by the day. Mexican figures have it that a quarter of the population is already here, that's the lower class. And a recent poll of remaining Mexicans showed that half of everyone left...the middle class, would head north in a heartbeat.
This should scare us and Mexico, too. They're admitting that entire villages are vacant, states (provinces?) depopulated, poverty more widespread. Furthermore, it's not just Mexicans who'll risk life and limb to get a decent life. It's everyone else below the Rio Grande, millions of Chinese (and China just refused to take back 68,000 illegals we caught in the US and probably told to show up in court), and Africans, to name but a few. So what are we to do? (Whistling past the graveyard won't work. We already tried that.)
And you know this how...? You can believe that 50,000,000 more than the ENTIRE population of Mexico and Central America are going to wonder up to the United States, but I don't.