A federal judge has ruled that a predominantly white Alabama city may separate from its more diverse school district, even though the judge concluded the action was motivated by race and sent messages of racial inferiority and exclusion that “assail the dignity of black school children.”

Gardendale, a bedroom community of Birmingham, has been pushing for years to form its own small school system. That would mean leaving the school system of surrounding Jefferson County, where black students outnumber whites.

Backers of the secession have said that are seeking local control over schools, not racial segregation. But opponents say that the separation is deeply tied to race and should not be allowed in a place that has been struggling to desegregate its schools since black families first sued a half century ago.

Judge Madeline Haikala of the U.S. District Court in Birmingham – who oversees Jefferson County’s long-running desegregation efforts – issued a ruling late Monday that fully satisfied neither side, charting a path forward for a breakup that she said had been “deplorable” in some ways.

Lawyers for black plaintiffs, who had sought to stop the secession, said their clients felt both vindicated by the court’s findings of intentional discrimination – and perplexed by the decision to allow the separation to move forward.

“It’s hard to square,” said Monique Lin-Luse, a lawyer for the NAACP Legal and Educational Defense Fund. “We’re still reviewing what our options are and response will be.” U.W. Clemon, a former federal judge who also represents the plaintiffs, said they would likely ask the judge to reconsider her opinion.

The Justice Department, which had opposed the separation, declined to comment on the ruling.

Haikala’s 190-page decision recounts the decades-long battle over school desegregation in Jefferson County, including multiple efforts by affluent, majority-white cities to splinter off and form their own school systems. It is a history that has left the county with a shrunken tax base and a growing percentage of low-income and minority students.

Against that backdrop, the judge offered a blistering critique of those who organized Gardendale’s effort to splinter from the county system. Pointing to Facebook posts and public statements, Haikala concluded they clearly saw secession as a way to control the demographics of city schools, erecting a barrier to black students who transferred from other parts of the county.

“Non-resident students are increasing at a alarming rate in our schools,” one organizer wrote on Facebook. “Those students do not contribute financially. They consume the resources of our schools, our teachers and our resident students, then go home.”

Such messages send a clear message to black students – many of whom live miles away in a community called North Smithfield, and attend Gardendale’s middle and high schools under a decades-old desegregation plan – that “these schools are not yours, and you are not welcome here,” Haikala wrote.

A flier distributed to Gardendale residents before a vote on whether to secede delivered “an unambiguous message of inferiority” to black students, Haikala wrote. The flier, with an image of a white child, asked, “Which path will Gardendale choose?”

It offered two choices: A list of predominantly black cities, whose schools remain part of the Jefferson County system, and a list of predominantly white cities – “some of the best places to live in the country,” the flier said – whose schools have broken away over the years.

Haikala decided that while she could opt to block the secession, given that it will likely get in the way of desegregating Jefferson County schools, she would allow it nonetheless – in part out of concern for black students, who she said would be likely to bear the blame if she refused.

Black children from North Smithfield who are currently bused to Gardendale are in a “catch-22,” she wrote, and without a concerted effort by the city’s leaders are likely to feel unwelcome no matter who runs its schools. Gardendale proposed including North Smithfield students in its new school system only after leaders of the secession effort concluded that it was essential to win court approval. “This is a tragic consequence of the way in which the Gardendale Board attempted to separate,” she wrote.

Under her decision, Gardendale may begin operating the two elementary schools within its boundaries beginning in fall 2017. If the city shows good faith in carrying out desegregation efforts at those schools over the next three years – including by allowing and paying for transfer students and appointing a black member to the all-white city school board – it may be allowed to take over the middle and high school within its boundaries.

Even then, Gardendale would have to pay Jefferson County for the high school building that sits at the center of town, which cost the county more than $50 million to build. The high school plays a key role in the county’s efforts to integrate, using career and technical education programs to attract students from far more segregated areas.

Patrick Martin, Gardendale’s superintendent, did not respond to an email seeking comment. In a statement posted to Gardendale’s website, Chris Segroves, president of the Gardendale Board of Education, said that the board was reviewing the order.

“We know that the community is anxious and ready to achieve its goal of a locally led public school system. We are too,” Segroves said. “While the Court’s order is progress and represents a significant development in that process, we must ask for your continued patience and prayers in the coming days as we work through this together for the betterment of our community.”

Under Alabama law, cities of more than 5,000 residents can form independent school systems, and Gardendale had argued that the federal court should have no say over its separation. “Things have changed” since the Supreme Court’s landmark decisions on school segregation, Gardendale argued in a brief, and federal courts must “open their eyes to the condition of the present.”

Haikala forcefully refuted that argument, writing that Gardendale’s message to black students that they are inferior and unwanted has been “unmistakable” and “intolerable.”

“The Court may not turn a blind eye to that message,” the judge wrote.

Erica Frankenberg, a professor at Penn State University who studies school segregation, said that the decision by Haikala – who was appointed by President Barack Obama and is relatively new to the Jefferson County case – is a significant departure from previous court decisions that allowed majority-white cities to splinter away from larger school systems without publicly explaining or grappling with the consequences.

Frankenberg said the decision is also an important defense of the federal government’s role in monitoring and overseeing school desegregation. “You can’t just say that the passage of time has gotten rid of the prior segregation,” she said.