These aren't just slabs of cement and iron we're talking about. These walls will seismic sensors. IR tech and ground penetrating radar. As I said, its a deterrent. Its not a fix all. If it stops 10% over 10 years, it would save American tax payers over 100 billion dollars. Most immigrants are like water. They will seek the least path of resistance. Walls in remote, hard to patrol areas will funnel invaders to places they will get caught. We have approximately 18000 border control personnel on the southern border. About 40% are administrative and not in tue field. That leaves less than 10000 to patrol 2000 miles of border. That's about one agent per 1/4 mile if they traveled alone and worked 24/7/365. Realistically, its about one agent per mile. That's still considering their travel alone, which they don't. A wall would be a great tool for the CBC.That's the real kicker though - according to the subject matter expert in the link I provided, even an authorized wall will not have a chance at being completed in a couple of years, let alone in a couple of presidencies.I entered this post late and didn't have time to read each and every contribution. With that said, as someone who served in the military and as a government contractor, I can tell you there is no other obstacle as formidable as a wall when trying to penetrate a perimeter. Yes it can be defeated. But in most cases, not by people carrying all their worldly possessions and tired from a long haul. A wall is a great deterrent. If you do the math, if a wall only stops 10% of the invaders, it will more than pay for itself in only a couple of years.
That said, we should also set and enforce extreme penalties for those in our country that don't obey immigration laws. No more petty fines for those employing, housing, transporting, aiding or abbeding illegal criminal aliens. The laws on the books already make all these things illegal. If illegals have no place to work, live, get aid or help, they will not come and the ones here will self deport. Federal, state and local governments must also be held accountable. They break immigration laws with impunity.
This is the federal law on record. Read it and you will be surprised how often our "leaders" break the law and how seldom the law is upheld.
Danger Aaron posted photos of a simple way to defeat a wall: a shovel.
There are far more reasons not to have a wall than to have a wall. As I said before, Trump's biggest campaign promise was the promise for a wall. Even if (read: when) the wall never materializes, he will continue to push for it because it'll get him votes next year, efficacy be damned.
If you have the time, please read through the link I posted. The author more than makes a case against the impracticality, and impossibility, of a border wall construction project.