The past few years have seen an absolute change in the correlation of forces. It used to be that a few policy wonks would write essays assailing union rules that protected mediocre teachers; these pronouncements were greeted with skepticism in the media and produced no political movement. Now powerful political players, most notably President Obama, are making such arguments. The unions feel the sand eroding under their feet. They sense their lack of legitimacy, especially within the media and the political class. They still fight to preserve their interests, but they’ve lost their moral authority, as we’ve seen in New York City, Denver, Chicago, and even Washington, D.C.

David Brooks in The Atlantic Magazine.