The Supreme Court’s junior member, Justice Stephen Breyer, often seems to reflect the innately cautious character of the current Court. Lawyers learn that when Breyer speaks up, it may be time to restrain the reach of their arguments. That was clearly so when the Court heard a case that disability rights activists consider to be their equivalent to Brown v. Board of Education.

The case, Olmstead v. L.C. and E.W., is viewed by those activists as potentially ending the segregation of mentally disabled individuals in psychiatric hospitals, allowing many of them to live in homelike centers in the community as they get training to function in the mainstream. But that has the potential, as Breyer and some of his colleagues saw it, of carrying deinstitutionalization too far. Olmstead appears to be the most important of a handful of disability rights cases before the Court this term�including four argued in the same week.