Re: the Feb. 9 article "Bannon, others tout proposal for privately built border wall."
A wall is defined as a barrier or defense. One possible form of defense could be, clear trees and shrubs that could conceal a human from a 60-foot wide strip, north of the border between the U.S. and Mexico. Blade a "country road" near the middle. Make it wide enough for two Border Patrol vehicles to pass. Do not destroy wildflowers or native grasses within the 60' strip. Even encourage the propagation of short plants.
In California, Arizona and New Mexico, most of this strip of land is owned by the government. It was set aside in 1907 as an anti-smuggling effort by President Theodore Roosevelt. This would allow installation of towers holding high tech optical, radar and infrared sensors. Install as many as needed to watch the border, from sea to shining sea. Install vehicle barriers set four feet apart between towers. Steel "hedgehog" devices installed on Normandy Beach during WWII can't be knocked over.
A barrier can be horizontal!
Disclaimer: As submitted to the Arizona Daily Star.