Of the many lousy things the City of Chicago has done in the years I've lived here, perhaps none has left a moral stain quite like that of the "reform" of public housing. The housing authority, once known widely for its high-rise housing projects, systematically tore them down and sold the property to developers. The idea was to replace the projects with mixed-income developments, comprised of equal parts public, affordable and market-rate units. But it was never clear how there would be enough public units to replace the many that were demolished—i.e., where all those poor, mostly African-American people were supposed to go. 

Most received rental vouchers and looked for privately owned places. But vouchers were about the only support they got—a tremendous missed opportunity, as the Chicago Reader explains well in this article from last year's mayoral election:

The tearing down of the high-rises offered an extraordinary chance for widespread desegregation, which might have happened had the displaced residents gotten more counseling and support to help them move to middle-class neighborhoods. But a study of the plan in the 2009 Journal of Public Affairs found that most of the displaced residents merely moved from their vertical ghettos to horizontal ones, settling in "disadvantaged, predominantly black neighborhoods."