I think there's no question that the barriers, the fences and in certain urban areas, the walls, have had an important effect in terms of increasing the manageability and the security of the border. But in fact as Secretary of Homeland Security General John Kelly acknowledged at his confirmation hearing, walls and barriers alone are insufficient to insure security.

The law change during the Bush administration gave the Department of Health and Human Services a central role in relocating Central American minors in the United States.

Migrants come up and no longer seek to evade the Border Patrol, but are actually left at the border by their smugglers. And they seek out Border Patrol agents or Customs and Border Protection officials to surrender to them and request political asylum. That's the way in which they get entry into a system that will eventually release them into the country.

Mexico now has the 13th largest economy in the world. The Organization for Economic Cooperation and Development predicts it will have a larger economy than Germany by 2042.

The work the Mexicans are doing in terms of migration control on Mexico's southern border is crucial to our own border security.

There have been enormous advances since 9/11 to build a very robust set of targeting procedures and watch lists to screen travelers coming to the United States. The National Targeting Center in Virginia run by Customs and Border Protection checks the background of every traveler who seeks to enter the country.

Our security in a global world must be looked at on a continental basis.