Since 1986, the U.S. has steadily built an infrastructure on its Southern border and inland. All told, the nation has spent nearly $200 billion in today's dollars. Roughly 80,000 government workers depend on immigration enforcement, along with defense contractors large and small. NPR's Ted Robbins reports immigration is down, but there's no end in sight for the border-industrial complex. (This piece initially aired Sept. 12, 2012, on Morning Edition).