It depends on what you're trying to achieve. If you think that a wall on the southern border will stop determined groups of people, this proves it wrong. It proves that a border just gives a false sense of security and determined people will tunnel under the wall, or simply sail around.
If your fear is some flood of central and south americans coming across and taking jobs, then a wall may help a little. But in the end a wall is mostly a false sense of security... because a wall still needs a lot of the same man-power to monitor to ensure no one is travelling over, or tunneling under, or put a hole in it. In the end, you still have to man the wall.
victor809 wrote: