The nationalism and the protectionism that was built into the Mexican Revolution in 1910 and that characterized the Mexican attitude to the United States for much of the 20th century were difficult to overcome. But that actually has occurred. And the cooperation, trust and confidence that have been built is not something that should be abandoned without great consideration for the potentially grave consequences to the United States.

Mexico has become a robust democracy with a robust press and an active legislature. It has gone from being a sending country for migrants to a transit country, and increasingly a receiving country for migrants in its own right.

In today's digital online world, those who don't share information will be isolated and left behind.

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.

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.

If you build a 50-foot wall, you'll soon be confronted with a 51-foot ladder.

In the last two years, the Mexicans have detained nearly 400,000 migrants whose intent was to come to the United States. The Mexicans return the detained Central American migrants by bus or by air to the countries they come from.