The reason it is going on is because drugs have been decriminalized.
Mexico decriminalized ALL drugs including opiates, LCD, and heroin. It’s cheaper to buy heroin or LSD than to buy a beer in and around the border.
Illegal aliens, crossing the border, recognizing the market for drugs and the lack of imprisonment for nearly any crime of a personal nature in some quantities, have nothing to risk by bringing some illegal drugs across the border on foot and selling it for cash the deeper into our country they migrate.
The solution to the problem isn’t from without but from within. From God’s perspective, man isn’t breaking the Law, rather the Law breaks man. If people want to avoid problems, all they have to do is respect legitimate authority and follow His guidance in what He provides. Just like myself, though, we all slip and get arrogant thinking we can get along on our own independent of Him, and we get bit. Some more so than others.
Whatever works for you though...