In fact, however, unions don't always have control over all the pieces for which they're attacked.
"I get angry when criticisms are targeted at unions that should be placed on poor administration," says Susan Moore Johnson, a professor at Harvard's Graduate School of Education in Cambridge, Mass. Districts, for instance, would have a far easier time firing incompetent teachers if they did the thorough evaluations they are supposed to do, she notes. "Unions get blamed because it's too hard to understand," she says.
Moreover, when unions are taken out of the equation – in charter schools or in the South (most of which is nonunionized) – the educational results aren't any better, says Richard Kahlenberg, a senior fellow at the Century Foundation in Washington. "There's very little evidence that the existence of a strong teachers union or collective bargaining has a negative impact on student achievement," he says.
Still, Mr. Kahlenberg agrees with most education experts that as unions look to their future, they need to shift their outlook. "The biggest problem for unions is that they're perceived as defending incompetent teachers," he says, noting that better evaluation systems, including peer review, could help.