I live in San Diego and I am of the belief that the barrier works. The Border Patrol supports my belief..."We have continuously been told by Border Patrol Agents that the barrier along the Southern border helps prevent illegal entries, drugs, and weapons from entering the United States, and the numbers prove it."
Having said that...I don't believe that a border wall is the "be all end all" that some Trump supporters believe. I do think it's an important piece of border security that a lot of the southern border is missing. In other words, I'm all for what will support the Border Patrol agents in doing their job.