Comparing that ranking with Frey’s analysis—which looked at changes in the 20-and-younger population for each state between 2000 and 2014—produces results that are ominous for the nation’s future economic vitality and social stability.

The 15 states that the foundation ranked as producing the best outcomes for kids are mostly clustered in New England (New Hampshire, Massachusetts, Maine, Vermont, Connecticut), the Midwest (Minnesota, Iowa, Wisconsin) and the mid-Atlantic (New Jersey, Maryland, Virginia). But in nine of the 15 highest-ranked states, the number of young people declined from 2000 through 2014, Frey found. Only in Utah and Virginia did the number of young people increase by at least 5 percent.

The 15 states that Casey ranked as producing the worst outcomes for kids are clustered in the Sun Belt (ranging west from South Carolina, Georgia, and Florida to Texas, Nevada, and California) and the Appalachia region (West Virginia, Tennessee, Kentucky). In nine of the 15 lowest-ranked states, the number of young people increased between 2000 and 2014. The increase reached double digits in six of those states.

Overall, nearly 37 million young people—representing 45 percent of Americans under 20—now live in the 15 states at the bottom of the Casey foundation list. Just 15 million youth, representing only 19 percent of that same age cohort, live in the top 15 states. Moving forward, this discrepancy may only widen: Of the 15 states that experienced the largest percentage increases in their youth populations, nine rank in the bottom 15 and just one is in its top 15.

Several chasms separate kids’ experiences across these states. For one, the share of children in poverty is lower than the national average (which was 22 percent in 2013) on all 15 states topping the list. Meanwhile, the share of children in poverty exceeds the national average in all 15 states at the bottom, including Texas (25 percent), Arizona (26 percent), and Georgia (27 percent). Results for high-school graduation rates and access to health insurance follow similar patterns.

Another chasm that separates the highest and lowest-ranked states is diversity. Nonwhites represent a majority of kids under 20 in just two of the 15 highest-ranked states, while they account for a majority of the under-20 population in eight of the 15 lowest ranked states (including Georgia, Florida, Texas, and California), and at least two-fifths of the age cohort in four others.

The Sun Belt states seem to face the most acute challenge of putting more kids of color on track to the middle class. But that is increasingly becoming a national phenomenon. Frey’s data shows that the absolute number of white kids under 20 has declined in 46 of the 50 states since 2000. Against that backdrop, a failure to elevate the children of color, who will comprise a growing share of the workforce almost everywhere, will hurt not only the states in which they live, but also the nation’s competitive edge.