In a recent New York Times op-ed, University of California at Berkeley professor and former Obama adviser David Kirp proclaims that forced busing “made all the difference in the lives of black children — and in the lives of their children as well.” If integration worked, he asks, why have Americans rejected it?

Kirp is one among a growing number of left-wing academics who have begun to call for a revival of student assignment policies that create racially heterogeneous public schools by forcibly busing school children. While much of the talk about race-based busing has come from intellectuals on the Left, a small but growing segment of the general public has warmed to the idea.

Like many Americans, Kirp and his allies are frustrated by the sizable achievement gap between white and black public school children — and justifiably so. The achievement gap in states like North Carolina is startling, albeit typical. Less than half of North Carolina’s black students in grades three through eight are proficient in reading and math. Proficiency rates for their white counterparts are approaching 80 percent. The achievement gap between black and white male students is even larger.

Kirp does not believe that simply mixing black and white students together brought about improvement in the lives of black children (and their children). He acknowledges that there was no “white magic,” as Abigail Thernstrom once called it, that passes academic achievement from white students to their black counterparts.

Rather, he suggests that race-based busing forced schools to spend more on the education of blacks. This additional spending lowered class sizes, improved school facilities, and upgraded educational materials and equipment. He also speculates that busing encouraged teachers and parents, particularly the affluent ones, to maintain high expectations for all children.

If Kirp is correct, one wonders why busing is necessary at all. Presumably, school districts simply could allocate additional resources to predominantly black schools and hold those schools to high expectations.

Despite his enthusiasm for the idea, Kirp is not optimistic about the immediate resurrection of race-based busing. He identifies two significant barriers. First, what he calls a “hostile majority on the Supreme Court” ruled that public school districts no longer could use race as a factor in student assignment decisions. For decades, the courts debated the legality of race-based busing, but the issue finally was put to rest by the U.S. Supreme Court in 2007. In Parents Involved in Community Schools v. Seattle School District No. 1, a 5-4 majority ruled that using race as a factor in student assignment was unconstitutional.

Second, he finds that no “vocal pro-integration constituency” exists to defend forced busing based on race. Kirp’s dilemma is that the “vocal pro-integration constituency” has adopted a new strategy: income-based busing.

The Parents Involved ruling did not disqualify the practice of using the percentage of students receiving federal free and reduced price lunch, a commonly used proxy for family income, to assign students to schools. Century Foundation fellow Richard Kahlenberg, a leading advocate of busing, pointed out that income-based student assignment policies would “indirectly promote racial integration in a manner that is legally bulletproof.” Kirp believes that income-based assignment policies are useful, but he is among those who strongly prefer a return to forced busing based on race.

For proponents of race-based busing, overturning Parents Involved is a long-term goal. For now, they will continue their efforts to cultivate a “vocal pro-integration constituency” through universities, advocacy groups, and the media. As a result, North Carolinians will hear a lot more about forced busing in coming months.

Dr. Terry Stoops is director of education policy at the John Locke Foundation.