The law primarily affects towns that have racially mixed populations.

Because it affects only individual districts and does not require regional desegregation efforts, it does not affect districts that have nearly all-white or all-minority enrollments.

In most cases, districts voluntarily comply through redistricting and other measures to correct school-by-school imbalances. The state has gone to court only once, seeking enforcement of a racial balance plan for a school in Waterbury.

Blumenthal said Thursday that it remained to be seen whether any Connecticut districts could cite the new Supreme Court ruling to defend themselves if they are ordered to shift their student populations to better balance their schools' racial makeup.

However, the ruling will not affect the voluntary desegregation measures included in the Sheff v. O'Neill court case settlement, he said.

Those measures include the establishment of magnet schools, programs in which city children fill open seats in suburban districts, and other programs.

The desegregation strategies were part of a 2003 settlement after the state Supreme Court ruled that segregated schools in Connecticut are unconstitutional under state law.

The settlement called for a target in which at least 30 percent of Hartford's children would attend racially integrated schools by 2007.

Those goals were not met. A report by Trinity College researchers found that only 9 percent of Hartford's students who are primarily black and Hispanic attend schools that have enough white students to qualify as racially integrated under terms of the Sheff settlement.

Officials are currently working on updates to the settlement agreement.

--Associated Press