Do you know the story of the Incredible Disappearing Border Fence? It's an object lesson in gesture politics and homeland insecurity. It's a tale of hollow rhetoric, meaningless legislation and bipartisan betrayal. And in the run-up to the Iowa caucuses, it's a helpful learning tool as you assess the promises of immigration enforcement converts now running for president. Last fall, Democrats and Republicans in Washington responded to continued public outrage over border chaos by passing the "Secure Fence Act." Did you question the timing? You should have. It's no coincidence they finally got off their duffs to respond just before...