cuisinart8 wrote:trying to close the border would be pretty much impossible and the cost would easily outstrip any potential benefits. The border with Mexico ishuge. Completely closing a total of almost 2,000 miles of border would be difficult even if a large part wasn't an inhospitable desert. I doubt even deploying the whole US Army would do the job- there's just too much to patrol effectively.
Not to argue one way or the other, but just for reference, the
Eisenhower Interstate Highway System currently spans 46,876 miles.
That, just by itself, is enough to span the U.S-Mexico border over 23 times.
In terms of time: the EIHS was substantially complete after 30 years. I suspect there's enough unallocated workforce in the U.S. today to finish a full wall in five years. The U.S. Bureau of Labor Statistics reports that some
90,000,000 people aren't working or aren't looking for work. 70 million of those are between the ages of 16-17 and older than 65, as well as those in two- and four-year colleges, leaving 20 million. If half of those are male (assuming we'd only want burlymen building a wall), that's roughly 10 million men available for construction work.
Let's further assume that 2 million of those are physically unable to work, leaving a total of 8,000,000 workers. With a U.S.-Mexico border length of 1,989 miles, if all 8 million men could be allocated to wall-building, that comes to over 4,000 men per mile.
You could probably build anything pretty quickly with that kind of labor, including a functional wall spanning the entire U.S.-Mexico border. (For comparison, approximately 15,000,000 U.S. men served in WW II.) You probably wouldn't need anything like that many workers, though.
Of course all this is just back-of-the-envelope calculation; it ignores the impossibility of actually getting millions of men shipped to the southern border to build anything.
But I think it does show that, if America actually wanted to build a southern wall, it absolutely has the capability to do so.
Again, I'm not saying it should; I'm saying it could.