Beyond saving money, Bobb sees his mission in broader terms: to improve the system's miserable academic performance. Again, the situation is dire. Last month brought news that more than three-quarters of the 900 eighth-graders who took a national math exam scored at "below basic" levels. In October 2008, some 57% of Detroit third- through eighth-graders essentially failed a state writing test. Detroit's graduation rate is 58%. "The system is academically bankrupt. This is almost academic homicide," Bobb says.

Experts point to Atlanta; Charlotte, N.C.; and Denver as big-city school districts that have rebounded in the hands of strong managers. Detroit presents a very different situation. The tax base is nearly gone. Poverty and unemployment are far more pervasive than in most other major American cities. Many adults lack the basic skills necessary to qualify for the high-tech jobs officials are desperately trying to attract to Michigan, which has the U.S.'s highest unemployment rate. Home values, on which property-tax revenues are based, have plunged to pennies on the dollar. Over the past decade, the Detroit schools weren't merely mismanaged. They were abandoned.

All that prompted Granholm, a Democrat, to seize control of Detroit's public schools in the fall of 2008 and then look for someone to fix them. After a wide search, she settled on Bobb, who had a reputation for restoring fiscal sanity to city governments — including managing public-school-system budgets. When Bobb arrived last spring, here's what he found: Contracts had been stuffed in office drawers. The district couldn't afford new books. Gas was siphoned between buses. The district had to borrow money to pay its employees. There wasn't even a chief financial officer managing the system's $1.3 billion annual budget. "Detroit is unlike anything I've ever experienced. It's a lot worse than I anticipated," he says.

Denial was a problem too. Shortly before Bobb took over, Detroit's school board okayed a budget that it claimed had an $8 million surplus. Bobb's assessment showed a budget deficit of $303.5 million. He's since reduced the deficit partly by trimming the system's job rolls from about 14,000 to about 13,000. He's closed 29 of the district's 194 schools and hired outside firms to restructure 17 others. And in what may be his most inspired move, Bobb has asked some 2,600 volunteers to donate 360,000 hours to helping kids read.

Bobb knows from experience that he is fighting an unconventional war. Born in New Orleans, he grew up mainly on a southwest Louisiana sugarcane plantation, where his grandmother worked as a maid. During summers, he worked in sulfur pits; to cover tuition at Grambling State University, he buffed floors. He moved quickly through a series of city-management jobs in Kalamazoo, Mich., and Oakland, Calif. In 2003, Washington's then mayor, Anthony A. Williams, hired Bobb as city manager and deputy mayor; he managed an $8 billion annual budget and some 20,000 employees. Three years later, he was elected president of D.C.'s board of education. After that experience, why would anyone want to take on the task of saving Detroit's public schools? "I wanted to go to an urban school district, the roughest and the toughest. Why? Because I understand the dynamics, the grit, the opportunities that are prevalent in urban America."

Bobb acknowledges that the cost-shaving measures have made some high school classrooms "look like lecture halls." They have also raised the potential for clashes between students from rival schools and neighborhoods suddenly thrown under the same roof; as a result 137 guidance counselors cut by Bobb were later hired back. Bobb had a similar change of heart after 20 piano teachers were dismissed. "You go back to your apartment and think, How can you have a school of music without a piano teacher?" Bobb says. So he hired them back too. Barbara Byrd-Bennett, Bobb's chief academic officer and a former CEO of Cleveland's public schools, says she often greeted Bobb's proposed cuts with a single question: "Is this good for the kids?"

Meanwhile, Bobb is drafting broad academic reforms to bolster school-administrator, teacher and student performance. He is establishing systemwide standards for what classes a student needs to have passed to be promoted to the next grade. He has shuffled dozens of principals, often from relatively high-performing schools to less than stellar ones, and he may extend the school day. In the next 18 months, he wants significant gains in the percentage of fourth- and eighth-graders who perform at grade level in math and reading. By 2015, he wants 90% of all students to complete at least one Advanced Placement course before graduating. "Those are very ambitious goals," he admits. And ultimately they may be hindered by politics: Detroit's elected school board charges he is overstepping his financial portfolio and must relinquish control of academic affairs to the acting superintendent.

In dark suits and cowboy boots, Bobb has a commanding presence and seems to be everywhere: at school-bus depots, at barbershops, churches and grocery stores to prod parents to get their kids to school each day — on time. His schedule is often double-booked, partly because he knows he must quickly build support for his plans, like a $500.5 million proposal — approved by voters last November — to build or renovate 18 schools. He has recently signed on for a second year. It won't be any easier than his first. "Change is painful," Bobb says, adding, "We cannot be afraid to win — or fail."