BOSTON

The Supreme Court ruling Thursday that prohibits schools from considering race when assigning students, except in limited cases, could revive a failed challenge to the city of Lynn's controversial desegregation plan and imperil similar policies around the state.

The Supreme Court's 5-4 ruling rejected integration plans in Louisville, Ky., and Seattle, though it did not say race could never be used when considering school assignments.

Lynn's system allows race to be considered when children request transfers to schools outside their neighborhoods. At least 20 school districts statewide have voluntary desegregation plans that consider race, including Brockton, Salem and Worcester.

Attorney Chester Darling, who represented parents who challenged Lynn's policy as unconstitutional, said he's prepared to file a request in federal court to immediately end it.

He said Thursday's ruling opens the door to resurrect his case because though its specifics differ from the Supreme Court cases, it shares the same principle.

"The basic thing is the awarding or withholding of a governmental benefit on the basis of race," he said. "That was the issue in each of the three cases."

Nicholas Kostan, superintendent of schools in Lynn, said it appears to him the city will have to abandon the 20-year-old policy, which he said has worked to promote good relations between races.

"I'm disappointed because the people of the city have supported the plan," he said.

But Richard Cole, who handled the Lynn case for the state attorney general's office, said Justice Anthony Kennedy's concurring opinion made it unlikely the ruling would impact Lynn.

Kennedy differed from his conservative colleagues by saying that under narrow exceptions race can be considered when schools devise diversity plans. One exception allows race as the only consideration if it can be proven there was no alternative and there is a crucial need for the plan.