Drugs don’t come overland. They come in through the sea ports, through the road network, and through aircraft. The wall is not going to end drugs coming into the country or even put a dent in it. There are other reasons justifying the wall but the opioid epidemic is not one.
You obviously don't live in Arizona. They come by the tons everyday across land.
I have word that military transport jets are flying in illegal drugs into Fr. Lewis AFB in Tacoma, Washington. What does that say to the problem? Pockets are being lined. Officials are turning a blind eye, blinded by the color of greeeeeeeeeeeen!