The U.S. Supreme Court today struck down -- on a 5-4 vote -- two school desegregation plans that involved assigning children to schools based on race.

The decision and the various justices' opinions discuss issues of race and diversity at length, but the court's majority opinion explicitly did not reverse its 2003 ruling upholding the right of colleges to use affirmative action, under certain circumstances, in admissions. (While such a reversal was not expected, some feared that the 2003 ruling could be attacked in these cases.)

The decision by Chief Justice John G. Roberts Jr. noted that the University of Michigan law school admissions plan that the court upheld in the 2003 decision known as Grutter v. Bollinger involved definitions of diversity that extended beyond race, and that considered a broader array of applicants' characteristics and qualifications than merely their racial identities.

A dissent by Justice Stephen G. Breyer, however, charged that the decision today ignored the Michigan ruling -- and numerous other rulings on race in educational settings -- in ways that could unsettle established law.

"The entire gist of the analysis in Grutter was that the admissions program at issue there focused on each applicant as an individual, and not simply as a member of a particular racial group," Chief Justice Roberts wrote in the court's decision, referring to the Michigan decision. "The classification of applicants by race in Grutter was only as part of a a 'highly individualized, holistic review review,' " the decision continued. "In the present cases, by contrast, race is not considered as part of a broader effort to achieve 'exposure to widely diverse people, cultures, ideas, and viewpoints.' "

Chief Justice Roberts also noted that in upholding the Michigan law school's plan, the Supreme Court had "relied upon considerations unique to institutions of higher education, noting that in light of 'the expansive freedoms of speech and thought associated with the university environment, universities occupy a special niche in our constitutional tradition.' "

A full report on the decision will appear tomorrow.