Rand is wrong on a “secure” border.
The US/Mexico Border is 2,000 miles long with few intersecting roads and mostly desert.
Make the USA as hostile as possible by enforcing existing Border Laws, and fining US employers $1,000 per day per illegal alien hired.
The Arpaio Desert Prison Model would be perfect to hold all captured border law breakers for the Federally required 6 months.
BTW, Sheriff Joe Arpaio claims that he feeds his prisoners for 22 cents a day.
Having been in the military, if we really wanted to secure the border with Mexico, we could. Not that hard.