This year marks two decades since two important events in the efforts to get Baltimoreans to face hard truths about Baltimore — David Rusk's warning that a city in decline could pull the whole metropolitan region down and the filing of a major class-action lawsuit to end decades of segregative housing policy that left the city with a disproportionate share of the region's poor. Rusk's book, "Baltimore Unbound,' declared that the city had reached a point of no return in social and economic decline, and that without a new metropolitan approach to governance, the suburban counties would next feel the...