Trumpers want their Wall even though it doesn't make a whole lot of sense.
It won't stop undocumented immigration, since far more of that comes from people who come in legally and then overstay their visas.
It won't stop "terrorists," since those are mostly either home-grown or come in with carefully legal documentation.
It won't stop the importation of drugs, since cartels tend to prefer to exploit the weaknesses of the legal entry points instead and rely on volume to make up their losses on what’s intercepted.
The use of technology to patrol the border and enforce immigration law is a nimble, effective, and cost-efficient approach to border control that's superior to building a wall.
So why do Trumpers want their Wall?
Of course the dim-idiot base need to have a physical manifestation of their need to wall out The Other in their race panic fear of being overwhelmed by the brown hordes, even if it's less effective and more costly.
But why are the establishment Republicans, the right-wing power brokers behind the scenes not pulling the rug out from under this ridiculous policy?
Because it's part of their "drown the government in the bathtub" philosophy:
[W]hen you are relying on technology to detect intrusions, you still need human beings, thousands of them, to actually take border crossers into custody. I have yet to see cyborgs or androids capable of making arrests. Believe me, the cost of training and putting even a single agent into uniform with badge and gun, then paying for 20-25 years' worth of pay increases and then a federal annuity after that, is an expensive proposition.
Second, if you are arresting aliens (which will by definition happen on our side of the line since I don't know of any morally acceptable technology to keep them across the border — you know, short of horrifying things such as electrified or mined areas, etc.) then the question arises of how much detention space you will apportion to the arrested aliens, and what your tolerance is for holding minors and partial family units in custody, possibly for extended periods. Yet if you let them go, as happens now routinely during the "catch-and-release" follies the government is forced into, then all of the billions spent on technology and agents was pretty much for nothing.
Third and finally, sometimes I laugh about this insistence on the importance of sophisticated intrusion technology when we've reached such a state that many aliens cross the frontier and immediately seek out Border Patrol agents to turn themselves in, knowing that our rules have become so dysfunctional that it's to their advantage to game the system. They understand our immigration system's ineffectiveness at expulsion and removal in ways that many ordinary Americans do not.
That's what a border barrier does: it blocks people out. Not all people all the time. But many. Tens of thousands. And if a wall (or steel slatted fence or whatever becomes the nom du jour) does that, many of the other dysfunctions — and, no less importantly, taxpayer costs, and amount and adequacy of detention space, and strains on social service systems — begin to ameliorate, buying the system time to heal itself and, maybe some day, we will have a Congress willing to enact meaningful legal reforms to the way our immigration laws are structured.
There seem to be a lot of Trumper fans among the ICE and border enforcement and detention crowd.
I wonder how many of them realize that much of the impetus behind building a border wall is to eliminate their jobs, their careers, and their pensions, and hand that money over to fabricators of cheap steel in China instead?
Businesses that rely on exploiting undocumented workers will still have docile undocumented workers to exploit — people who come in legally and overstay their visas — to keep down wages for workers generally.
But the small-government Republicans will have gleefully swept away a large group of what they consider expensive and expendable government-employed workers and decades of pension responsibility for them.
If you're a conscienceless social Darwinian psychopath, as many of the big funders on the right seem to be, that's a win-win. If you're a racist blue-collar worker hoping for race purity and economic WINNING, not so much.