We're all familiar with the old game of Russian Roulette, though most are more familiar with it figuratively than literally. Needless to say, there's a "great deal" of luck involved when playing this game, but eventually, you will lose and the room will be a mess.
In many ways, how we treat our southern border, assuming you go so far as to call it a border, is the same. The government keeps it's fingers crossed and hopes we'll continue to be lucky as to who is coming into the country, and why. Fact is, the govt. doesn't have a clue as to who comes in, or where they end up, or what their true intentions are. It's kind of like playing Russian Roulette with five bullets instead of one, meaning you will lose, it's just a question of when. Another scary fact is that we have absolutely no idea how many genuine threats to our nation have come across that border, nor do we know what they may have been carrying. To find that out, we'll have to wait for a large mushroom cloud over a major city, or wait to see tens-of-thousand of dead bodies covering our streets, airports, bus or rail stations, or some huge major sporting event. All it would take is a Coke bottle filled with some chemical weapon to get those results.
With the world getting more dangerous and crazy by the day, one would think a so-called rational society would think about this and take steps to stop it. Closing our border crossings and lining our border with armed troops would be a great start. And, it's very doable. Instead of wasting time, hundreds-of-Billions, and above all, valuable lives in Iraq and Afghanistan helping people who hate us, those brave troops could be protecting their own country and people. And it wouldn't cost us an extra dollar since we're already paying our warriors, albeit not nearly enough. Will we see this happen? No! The elected, lying, crooks in DC are not known for following rational, common sense advise. I guess we'll just have to wait for, that day...