An unofficial commemorative coin has been circulating among Border Patrol agents at the U.S./Mexico border, mocking the task of caring for migrant children and other duties that have fallen to agents as families cross into the U.S. On the front, the coin declares “KEEP THE CARAVANS COMING” under an image of a massive parade of people carrying a Honduran flag — a caricature of the “caravan” from last fall, which started in Honduras and attracted thousands of people as it moved north. (While the caravan included many women and children, the only visible figures on the coin appear to be...