He ruled that mention of race alone as the plan evolved was not enough to constitute violation of the students' right to equal treatment under the law, as the plaintiffs had argued.
"A basic principle underlying this case is that pure 'racial balancing' at the high school level, standing alone, would be improper," Baylson wrote, "but that considering racial demographics alongside race-neutral, valid educational interests . . . has never been held unconstitutional."
Though even Baylson had predicted an appeal was inevitable in the closely watched case, the ruling represented a substantial win for the district, which is under fire in another case involving alleged spying via webcams in students' laptops.
Superintendent Christopher McGinley reacted swiftly to Baylson's opinion.
"The district is pleased with the outcome, grateful for the understanding and support of so many, and hopeful that the entire community can now work as one on the many difficult educational challenges we face on behalf of all our children," he said through school publicist Douglas Young.
Plaintiffs' attorney David G.C. Arnold said in an e-mail from his BlackBerry: "We are reviewing the decision and considering our options at this time."
Kermit Roosevelt, professor of law at the University of Pennsylvania Law School, called the ruling "very interesting."
"My quick thought is that the outcome is probably right, but I question the reasoning," he said, and added: "It's a novel and provocative legal analysis that will almost certainly be appealed."
During a nine-day trial in April, the students argued that their right to equal treatment under the law was dashed by the district's 2009 decision to assign them to Harriton High School in Rosemont.
