Actually a wall does and would work. It Legitamitely will reduce the number of human trafficking, drug smuggling, illegal migrating, and money rings where USD goes over the border to cartel.
Yes. A wall does those things.
Walls keep out unwanted problems. If you don't think a wall will work, please see the razor wire wall Washington put up to keep out Trumpf Supporters.
Not many Trump Supporters have made it past that razor wire.
So which is - walls work or they don't? If they don't work, why aren't you crying out for Washington's razor wire wall to be torn down?