To focus Michael's argument a bit, to have a constitutional, 14th Amendment equal protection argument, one has to have "state action." (This law does not extend to private behavior.) That is why the Brown ruling was limited to legally segregated school districts. Corollary issues such as the lingering effects of state discrimination -- a concept I champion at every turn -- were beyond the Court's ruling and, indeed, beyond the reach of the law as it now stands. Pointedly, the foregoing "effects of slavery and segregation" rationale, if I have it right, has been explicitly rejected in affirmative action cases, which may be considered, though of a different "species" than school segregation by law, at least of the same "genus": remedies for past discrimination remotely or immediately imposed by the state.
As to Myrdal, I don't know how his watershed study was used by the Court, but I do know this: without actual evidence in court (the lower courts) in the nature of expert opinion or otherwise based on data duly collected and presented by a witness, it would be a monumental departure from all known evidentiary rules to "adopt" a hearsay study as the factual basis for a ruling concerning venues, I assume, the author didn't even study. The only conceivable mechanism for such a feat would be the concept of "judicial notice," which has only a tangential bearing.
