The squat brick buildings of Grove Parc Plaza, in a dense neighborhood that Barack Obama represented for eight years as a state senator, hold 504 apartments subsidized by the federal government for people who can’t afford to live anywhere else.

But it’s not safe to live here.

About 99 of the units are vacant, many rendered uninhabitable by unfixed problems, such as collapsed roofs and fire damage. Mice scamper through the halls. Battered mailboxes hang open. Sewage backs up into kitchen sinks. In 2006, federal inspectors graded the condition of the complex an 11 on a 100-point scale – a score so bad the buildings now face demolition. Valerie Jarrett, a senior adviser to Obama’s presidential campaign and a member of his finance committee. Jarrett is the chief executive of Habitat Co., which managed Grove Parc Plaza from 2001 until this winter and co-managed an even larger subsidized complex in Chicago that was seized by the federal government in 2006, after city inspectors found widespread problems.

Grove Parc has become a symbol for some in Chicago of the broader failures of giving public subsidies to private companies to build and manage affordable housing – an approach strongly backed by Obama as the best replacement for public housing.

As a state senator, the presumptive Democratic presidential nominee coauthored an Illinois law creating a new pool of tax credits for developers. As a US senator, he pressed for increased federal subsidies. And as a presidential candidate, he has campaigned on a promise to create an Affordable Housing Trust Fund that could give developers an estimated $500 million a year.

But a Globe review found that thousands of apartments across Chicago that had been built with local, state, and federal subsidies – including several hundred in Obama’s former district – deteriorated so completely that they were no longer habitable.