In
Poor People's Movements: Why They Succeed, How They Fail, Piven and Cloward study four American social movements, two from the 1930s and two from the 1960s, to identify patterns in protester behavior, political and social context, and state responses that might inform lower-class political movements in the future. And they determine that in any social social movement (and all social movements, for their purposes, come from the working classes), "whatever the people won was a response to their turbulence and not to their organized numbers." In other words, uncontrollable mass insurgency, not SMOs, are what cause changes in society and win more rights for oppressed groups.
The reason SMOs kill a social movement instead of fueling it is that organizational development involves creating a disciplined, orderly membership and on getting resources, usually from elites, to sustain the organization. Elites are more than happy to help fund these organizations, because they're a way of calming down angry people and bringing them into orderly obedience again - or at least a way of distracting them from their revolutionary goals. "Organizations endure, in short, by abandoning their revolutionary politics, and therefore SMOs kill social movements.
