Full at http://blog.cheapmotelsandahotplate.org/2011/01/04/radical-labor-education-part-2/
"While unions are indispensable organizations of the working class, they are not likely to lead a radical social transformation. They face inherent constraints. First, unions may replicate already existing divisions within the working class. Many occupations are segregated by gender. Nearly all coal miners are men. A union of coal miners is unlikely, therefore, to attack gender discrimination. It is more likely that sexism will become deeply rooted in the union itself. The same can be said about racial divisions. Black and white workers may cooperate in a strike and may work side by side, but this does not mean that the union will actively confront the racism that is pervasive in the United States. Second, unions are defensive organizations. In their day-to-day operations, they will be inclined to accept capitalism as a fact of life and try to do the best for their members within its confines. A union may begin with a radical perspective, but over time it is likely to accommodate itself to capitalism and “pragmatically” maneuver within it. In fact, acceptance of capitalism may become the ideology of a labor movement, as is true for most unions in the United States. Not only do U.S. labor leaders accept the system, but they have collaborated with employers to undermine attempts by workers here and abroad to forge radical labor organizations.
Despite their limitations, unions, as we have seen in Part I, teach workers many useful things simply because they are collective organizations. In addition, they have sought to actively educate their members through formal programs. These have taken several forms: teaching English to newly-arrived immigrants, training shop stewards, and establishing full-blown college programs and technical training institutes. Radicals have played important roles in union-based education programs, but it can be difficult for them to teach with an independent spirit. Union leaders are interested in practical education, with a focus upon training union officials to better perform their jobs as stewards, negotiators, and contract administrators, and they may not see the need for a liberal education, much less a radical one. They are seldom keen on a critical analysis of the unions themselves, no matter how badly one is needed." . . .