Hundreds of thousands of Mexican citizens, along with Mexican-Americans and Hispanics in general, hit the streets throughout the United States this past week in one of the largest displays of public outrage since the Vietnam-War era. The conventional wisdom was that the supposedly spontaneous outbursts of immigrant pride and anger took lawmakers by surprise. In response, politicians may backtrack on some of the tougher proposals concerning border enforcement, from constructing a wall to deportations. The media tended to emphasize the heartfelt anguish of the demonstrators, who often on selected televised clips carried American flags and were shown reciting the Pledge...