Teachers' unions have gotten rough treatment from commentators lately. Conservatives are accustomed to hating them, of course, but even some liberals, their presumptive defenders, are frustrated that union money helped defeat school-reform champion Adrian Fenty in the DC Democratic primary.

Matt Yglesias, generally no apologist for teachers' unions, does offer one argument in favor of them.  He notes that "the simple fact of the matter is that in a democracy there's no way to prevent a bunch of people in the same line of work from forming an association to advocate on their behalf." At least the teachers use their "clout" to "stand up against cuts in Social Security benefits" and lobby for financial regulatory reform and universal health care. "You don't see the American Medical Association or the Associated Locksmiths of America or many of the million other similar outfits doing that stuff." Whatever their faults, teachers' unions still stand as "cornerstones of middle class political advocacy."