People in our so-called Rust Belt have lost out, and politics and society have not been responsive either in providing the kind of additional support they need or to retrain them for jobs that are being created in the new economy.

Homeland security is inherently transnational today. There's hardly anything adverse that happens in our homeland that doesn't have a cause or effect that's generated abroad. Increasingly, we must rely on our allies and foreign governments to share information and data to secure our country.

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.

Most people who live at the border or are familiar with the border know that a Berlin-like wall stretching from San Diego to Brownsville is not necessary. And the costs would be prohibitive. And there are places on the border, such as the Arizona desert or the open terrain around the Big Bend in South Texas, where Mother Nature has created her own barrier that is not easily passable. Or if you do pass through it, you are easily detected.

The Mexican people are increasingly middle class, and Mexico has substantially become a middle-class society. This is true despite the significant poverty, and the class and geographic inequality that have deep historical roots.

Six million jobs in the US depend on trade with Mexico. Ten border states - six in Mexico and four in the United States - combined have the third or fourth largest economy in the world. Twenty-nine US states depend on Mexico as their primary export market.

People in our so-called Rust Belt have lost out, and politics and society have not been responsive either in providing the kind of additional support they need or to retrain them for jobs that are being created in the new economy.