The debate over border policy in the United States has reached levels of nonsense worthy of Lewis Carroll. On the right, you have presidential candidate Donald Trump tarring all immigrants from south of the Rio Grande as "rapists and murderers," and pledging to build a "huge" wall to keep them out. On the left, you have Democrats so high on the warm and fuzzy feeling of "embracing diversity" that they imagine an open-border policy of uncontrolled immigration is sustainable. (Hey, EU! How did that work out for you?)