As I was leaving the city and driving north on IH35 toward San Antonio, I was reminded of the tyranny that comes with a system of immigration controls. The tyranny came in the form of a domestic—i.e., inside the United States—checkpoint, one in which U.S. officials wield omnipotent, totalitarian power over people who drive through it.
About 30 miles north of Laredo, a driver goes over the crest of a hill and encounters an amazing and surreal site. At first, it seems like you're still in Mexico because up ahead is a permanent government highway checkpoint, one that you find on the border itself.
But this isn't the border. This is some 30 miles north of the border. It stands to reason that in a system of immigration controls, officials would have an immigration checkpoint at the border to control entry into the United States. In Laredo, there are international bridges that connect Nuevo Laredo, Mexico, and Laredo. They span the Rio Grande, which is the official border between Mexico and the United States.
Thus, when a person crosses the bridge from Nuevo Laredo into Laredo, he encounters a big permanent immigration (and customs) checkpoint. That shouldn't surprise anyone. That's the way a system of immigration of border controls work.
At that border checkpoint, an entrant has virtually no rights. He is required to answer whatever questions the immigration official asks him. He is expected to comply with whatever orders the federal officials issue. He is subject to a complete search of his person and his automobile.