The federal judge presiding over the race-based Lower Merion School District redistricting case said yesterday he would issue his ruling by the end of this month but expects the losing side to appeal his decision in the Third Circuit Court of Appeals.

"It's an interesting case, it's an important case, but it's a very close case," U.S. District Judge Michael M. Baylson said.

Baylson noted that this case was "factually different than any other case I've read."

The case stems from a lawsuit filed in May 2009 by nine black students who allege the district's redistricting plan discriminated against them. The students live in South Ardmore and say their neighborhood was carved out for redistricting because it has a significant black population.

Under the plan, the students, now in elementary, middle or high school, have to be bused to Harriton High School in Rosemont, four miles away. They want the judge to restore their option to attend either Harriton or Lower Merion High School in Ardmore, which is about a mile away and in walking distance.

The district has contended its redistricting plan was based on a goal of equalizing the number of students who attend both high schools, and on elementary- and middle-school feeder patterns.

Baylson, who presided over a nine-day bench trial in this case more than a month ago, heard arguments yesterday on how the U.S. Supreme Court's 2007 decision in Parents Involved in Community Schools v. Seattle School District No. 1 affects the Lower Merion case. That decision found it unconstitutional to reassign students based on race.

Chief Justice John Roberts, writing the majority 5-4 opinion, said the districts in that case "failed to show that they considered methods other than explicit racial classifications to achieve their stated goals."

Justice Anthony Kennedy, who appeared to be the swing vote, wrote a separate concurring opinion. In it, he wrote that a district may consider race to achieve a diverse student population but that race cannot be the sole factor in assigning students to schools.

Baylson said that in reading Kennedy's opinion, he believed if the Lower Merion case were to come before the Supreme Court, the court would rule 5-4 in favor of the school district. While race was a motivating factor in Lower Merion's redistricting plan, Baylson noted it was one of several factors the district considered.

David G.C. Arnold, the attorney for the plaintiffs, told the judge yesterday he disagreed. The difference in the Lower Merion case, he argued, was the way the district went about targeting the South Ardmore neighborhood.

"It matters how the children are cut up to go to which school," he said. "It matters."