"Look. No wires. What holds it up?" the magician's sideshow barkers used to say. They could have been talking about the U.S. economy. Telling ourselves that "America will always win in any free market," we let free trade flow in and out from a world where many workers – and not just assembly-line screw tighteners but computer programmers and call-center salesmen – make less in a day than even the poorest among us has gotten used to earning in an hour. Somehow we manage to keep sending all our money and factory jobs overseas, but still – so far –...