On Sunday, confirmed cases in California topped 6,200, compared with just 23 in Baja California. Arizona had 919 cases, dwarfing the 14 in neighboring Sonora. New Mexico reported 237 cases; in Chihuahua state, there were six.
The U.S.-Mexico border is the busiest in the world, with an estimated 1 million legal crossings per day. The neighbors’ economies are intertwined.
So why is there such a big difference in cases?