While it is true that thousands of people joined the Communist Party in those years because they were members of the hardscrabble working class (garment district Jews, West Virginia miners, California fruit pickers), it was even truer that many more thousands in the educated middle class (teachers, scientists, writers) joined because for them, too, the party was possessed of a moral authority that lent shape and substance, through its passion for structure and the eloquence of its rhetoric, to an urgent sense of social injustice.