President Obama’s Justice Department asked a federal judge to halt a program that gives vouchers to poor students, arguing that the use of vouchers “impeded the desegregation process” of failing Louisiana schools.

How do school vouchers, used primarily by black students, do that? “Students leaving these schools with State-issued vouchers impeded the desegregation process by increasing the racial identifiability of these schools,” DOJ argued in a petition filed last week. “[T]he loss of students through the voucher program reversed much of the progress made toward desegregation.”

The Times-Picayune provides an example of the segregation-by-scholarship that the DOJ decries. “In Tangipahoa Parish, for instance, Independence Elementary School lost five white students to voucher schools, the petition states,” Danielle Dreilinger reported Saturday. “The consequent change in the percent of enrolled white students ‘reinforc(ed) the racial identity of the school as a black school.’”

Jindal attacked the Justice Department for trying to impede the program. “After generations of being denied a choice, parents finally can choose a school for their child, but now the federal government is stepping in to prevent parents from exercising this right,” Jindal said. “Shame on them.”

It’s not the first time Obama has moved to crack down on charter schools that benefit low-income families. “The president doesn’t believe that vouchers are a long-term answer to our educational problems and the challenges that face our public school system, where the vast majority of — of students are educated in this country,” then-White House Press Secretary Robert Gibbs said in 2009 when Obama tried to cut funding for a voucher program benefiting Washington, D.C., students.