A border is a legally constructed thing that keeps people in opposing countries from crossing into each other's country. A wall is a physical object that keeps people in opposing countries from crossing it. What is the difference between a wall and a border since they both do the exact same thing?
The wall will cost money to build, maintain, and the fact that portions of a wall has been built and it has not detour illegal immigration because of the tunnel systems under it make it a stupid idea.
Before you write they can sensor the area and landmine it, well that will not happen and again the wall will cost money to maintain...
Also do you want America to be like East Berlin or North Korea?
The simpler answer is to go after the employers that hire illegals, dry up every avenue for money, hire more ice agents, and use the drones at the border, and punish sanctuary states and cities.
The wall does nothing but make you believe the issue is solved when it will never be solved until someone goes into Mexico and Central America and clean up that mess down there...
So let me state again enforce the laws on the books.
Hire more agents.
Use the drones on the border.
Punish states and cities that are sanctuaries for illegals.
If you do this it would fix a hell of a lot more than that silly wall!