Source: The Century Foundation

Nearly a decade ago, the U.S. Supreme Court ruled that school districts could not assign students to schools based on their race, dealing a serious blow to voluntary racial integration efforts nationwide.

But that decision in the 2007 Parents Involved case gave rise to a different strategy for achieving integration — one based not on race, but on class. The number of districts and charter schools that use socioeconomic status as a factor in student assignment has grown quickly from two in 1996 to 39 in 2007 to 100 today, according to a report released Friday by the Century Foundation, which has been studying and advocating for socioeconomic integration for decades.

That’s still a tiny minority of the nation’s 14,000 school districts. But there are 4.4 million students enrolled in these districts, nearly 9 percent of all students nationwide. To the Century Foundation’s Richard Kahlenberg, that’s a significant increase at a time when segregation of the nation’s public schools is on the rise, and when — after years in the policy wilderness — integration is attracting new attention as a tool to improve education.

Kahlenberg praised U.S. Education Secretary John B. King Jr. for using the bully pulpit of his office, as well as incentives embedded in federal grant programs, to promote voluntary socioeconomic integration. “He’s been a real champion, and I think it was kind of long overdue for the Obama administration,” Kahlenberg said.

The communities currently pursuing socioeconomic integration are in red states and blue, and in many parts of the country, though they are sparse throughout parts of the Midwest and Rocky Mountain states.

The Education Department, the Century Foundation and the National Coalition on School Diversity are co-hosting a seminar next week for other districts to hear from those with experience navigating the transition to politically sensitive integration plans.

Kahlenberg said he is hopeful that the momentum will continue should Hillary Clinton be elected president. The Democratic nominee chose a running mate, Sen. Tim Kaine (D), who brought up the nation’s history of segregated schools during the one and only vice presidential debate. His wife — Anne Holton, Virginia’s former education secretary — famously helped integrate Richmond Public Schools. And Clinton’s own campaign slogan, “Stronger Together,” is also the name of President Obama’s proposal for a new $120 million grant program to support voluntary integration of public schools.

Correction: An earlier version of this story misreported the year in which there were only two districts seeking socioeconomic integration. The story has been updated.