Keep in mind that 60% of all illegal immigrants enter the country legally. The federal government has no ability, and no plans to create a system to track visa overstays. Border security is important but does not address the current issue of illegal immigration.

Undocumented minors at the border or already in the country are not handled by the agencies most of us think of when we talk about immigration; DHS, INS, CIS, etc... These cases are handled by the Department of Health and Human Services http://www.acf.hhs.gov/programs/orr/programs/ucs/about