Won't a wall, supposing it's somewhat effective at mitigating unlawful entry over the surface, simply encourage even more risky behavior such as (more?) tunneling and/or attempts at entering via the Gulf?

Also, for cat lovers out there, you might want to note this detail that just adds to the suffering this will perpetuate:

Concern is shared with environmental advocates who say structures will run through public lands, habitats of endangered plants and species like the Ocelot, a spotted wild cat.

Finally, wouldn't the more modern, humane, and fiscally responsible solution to this whole issue be migration reform such that people can more easily, legally enter the country? More people become citizens, more tax revenue, governments' budgets may still be tight but more manageable (supposing they continue to insist on avoiding taxing businesses more).

Don't get me wrong, though, I realize a big part of why it's not being addressed that way is related to fearmongering, with another big part being exploited migrant labor.