President Obama has launched a new initiative to get American schools to teach computer science. Appearing at a Newark, N.J., middle school, the president suggested that students, especially girls and minorities, should learn “not just how to use a smartphone but to create the apps for a smartphone.”

If we lived in a country where most students were graduating from high school with good English and math skills and with a firm grasp of American history and government, we might be in a position to make time for advanced computer skills. But we don’t. Only about 68 percent of Newark’s students even graduate from high school.