The one proposed back then was very substantial and opposed, even by the BP union.
“The one proposed back then (2012) was very substantial”
Still like comparing apples to oranges. This is not just a wall.
In the first Trump Administration, Congress required extensive design analysis that delayed funding for a long time. Lots of engineers studying it, prototype flyoffs and red teams attacking designs. The result is what they called “Border Wall System” (now called “Smart Wall).
It is a comprehensive package that addresses the “Border Wall Calculus” of how long different breaching methods require in different terrain, what is required to reliably detect them, and time required for effective response, vs. the “disappearing time” for breachers at any give location (minutes to get away in the city, some rural areas without roads require days).
They looked at tunnelling under, cutting, ramming or blasting through, and climbing or flying over. The resulting package includes newly designed super barrier, all weather access road, and multiple systems of sensors and monitors, all tied into AI monitoring assisting the watch officer in the command posts.
This design is to achieve full operational control, not just help.