it may have been (i don't know enough to say), but that doesn't get at the question. if it was a small movement, if a sliver of the working class constituted the whole of the movement, the generalization may hold. 1/

if you want to claim he's wrong, you'd want to claim a substantial portion of the working class were anarchist or sympathized with anarchism (or with upscale severely limited government liberalism) more than with other more dirigiste movements. which is possible, but i doubt. /fin