Which isn’t to say the U.S. shouldn’t build a wall. America deserves a secure border, and if the current tools —patrols, motion detectors, drones, fencing, natural geographic barriers — aren’t enough, then the government has a responsibility to pursue other options. But building the wall would be much more difficult than candidate Trump pretends. Voters who are fed up with being promised the moon only to wake up to the same rotten status quo are a big part of Trump’s success. How angry would they be to find out their savior was no more capable of bending reality to his will than the men he replaced?