A study by the Southern Education Foundation reported an astonishing statistic last week: Nearly half — 48 percent — of the 50 million public school students in the U.S. now live in poverty. Moreover, since 2000, poor children have become the majority in public schools throughout the South and West, with Maryland and Virginia the only states in our region where middle-class students are still in the majority. Since it's long been known that academic achievement closely tracks family income, the demographic shifts in the public school population have broad implications not only for the country but for how educators approach the problems that keep disadvantaged children from reaching their full potential.

The foundation based its conclusions on the number of children who come from families with incomes so low that they qualify for federally subsidized free or reduced-priced school meals. It then used that figure as a rough equivalent of poverty, because a family of four can earn no more than about $41,000 a year to qualify for the program. Researchers found that children from such families were the largest group of students in 13 Southern states and the four largest Western states in 2011. Classrooms there are filling with an influx of youngsters who enter kindergarten already behind their middle-class peers, get less parental support and guidance at home, and are thus more likely drop out of school before graduating and less likely to go on to college.

The data also showed that while high-income, high achieving American children are more than holding their own against their peers in other developed countries, the large proportion of poor children in the nation's public schools is the main reason U.S. students overall lag behind their counterparts in Europe and Asia. That's why the report should be considered a national wake-up call that despite the push toward reform initiated by recent federal efforts such as the Bush administration's No Child Left Behind Act and the Obama administration's Race to the Top, America's public schools are still failing millions of poor students.

Yet the challenge posed by the presence of large populations of poor children in the public schools almost certainly can't be met solely through the traditional approaches developed to educate middle-class pupils. Teachers can't automatically assume the children in their charge have had parents who read them stories, took them to play groups to develop social skills or tried to develop their musical or artistic talents. In many cases low-income parents have poor language and literacy skills themselves and can't help their children with their school work the way middle-class parents do. Poor children are also more likely to have unattended medical conditions, such as asthma, that distract them in class and prevent them from learning as quickly as others.

It's often said that the schools can't make up for a lack of good parenting, yet increasingly that is precisely what they are being called upon to do. School systems that fail to take these new needs into consideration and act on them are unlikely to succeed in helping their children achieve — with consequences for both its young people and the country as a whole.

There already are models for this kind of expanded mission for public schools in the charter school movement, in the push for universal pre-kindergarten instruction, extended school days and longer school years, and in innovative experimental programs such as the Harlem Childrens' Zone in New York, which provides "wrap-around" social and counseling services to poor children throughout their academic careers. What is required is another "Sputnik moment" — a startling and pointed reminder that the nation's future is at risk unless it embarks on an all-out effort to improve the effectiveness of its educational system in order remain competitive in a rapidly changing world — and then the courage to act on it.