The claim that a fence could not help is ridiculous. The project is not just a fence that is built then abandoned to watch what happens. The fence is a tool to affect the busy migration corridors, perhaps focusing traffic into tighter zones easier to manage by the Border Patrol.
The biggest obsticle to this project is how insulting it is to Mexicans. This needs to be politically-correctified by emphasizing how it will raise the wages of Mexicans already in the US, by calling it one of these:
Fence of Empowerment
Enfranchisement Monument
Impenetrable Wall of Enfranchisement
Freedom Wall
US/Mexico Adhesive Zone
How about the enviro-friendly "Trash catcher" as I know its windy down there...