Why Bother?

The government has clarified the role of the 1,200 National Guard troops it is sending to the Mexican border: they will not be enforcing the immigration laws.

US National Guard troops being sent to the Mexican border will be used to stem the flow of guns and drugs across the frontier and not to enforce US immigration laws, the State Department said Wednesday.
The clarification came after the Mexican government urged Washington not to use the additional troops to go after illegal immigrants.

So evidently illegals will be able to thumb their noses at the Guardsmen as they stream by, as long as they are unarmed.