DETROIT — In 2009, Detroit public schools had the lowest scores ever recorded in the 21-year history of the national math proficiency test.

The district had a budget deficit of $200 million.

About 8,000 students were leaving Detroit schools each year.

Political leaders had to do something, so they rounded up the usual whipping boys:

Wasteful bureaucrats. In 2009, the governor appointed an emergency financial manager, Robert Bobb, a former president of the Washington school board, to run the Detroit district. Mr. Bobb is known nationally for his work in school finance, and recruiting him took a big salary, $425,000 a year. He has spent millions more on financial consultants to clean up the fiscal mess left by previous superintendents.

Greedy unions. Though Detroit teachers make considerably less than nearby suburban teachers (a $73,700 maximum versus $97,700 in Troy), Mr. Bobb pressed for concessions. He got teachers to defer $5,000 a year in pay and contribute more for their health insurance. Last week, the Republican-controlled Legislature approved a bill to give emergency managers power to void public workers’ contracts. If signed by the governor, Mr. Bobb could terminate the Detroit teachers’ union contract.