Vox Borders S00 E11 The wall of eyes trained on the US - Mexico border

"If you want to know a country’s deepest fears, look at its border."

There's more to the border than just a wall. This dispatch is from the Rio Grande River, on the Texas side of the U.S. border with Mexico. I embedded with border patrol, to learn about the technology, techniques, and challenges of monitoring a section of the border with over 300 miles of river.