The people who live in the region where the U.S. border meets the Gulf of Mexico never quite understood how Donald Trump's great wall could ever be more than campaign rhetoric.

In interviews with The Associated Press, they described how erecting a concrete barrier across the entire 1,954-mile frontier with Mexico collides head-on with the geology of the Rio Grande valley, fierce local resistance and the immense cost.

That's why an electronically fortified "virtual wall" with surveillance cameras, observation balloons and drones makes a lot more sense to people.

The locals are not convinced that a 30- to 40-foot concrete wall will cure the nation's immigration ills. Few were surprised when the president-elect seemed to soften his position after the election, saying that the wall could include some fencing.