WASHINGTON -- The Supreme Court's decision 50 years ago, although an immense blessing to the nation, also carries a melancholy lesson. It is that great events -- the school desegregation ruling was the largest judicial event since the Dred Scott case of 1857 -- have myriad reverberations, some beneficial, others not. Brown v. Board of Education accelerated the process of bringing this creedal nation into closer conformity to its creed. But the decision also encouraged the abandonment of constitutional reasoning -- of constitutional law. It invested the judiciary with a prestige that begot arrogance. And it seemed to legitimize a...