Seldom have so few been studied so hard by so many as have the members of the American Communist Party before 1941. But, as this outstanding work demonstrates, the attention is deserved if only to explain why, in such propitious times as the 1930s, the Party failed to achieve more than it did. The answer-the crippling effect of having to follow the Moscow line with unthinking rigidity-is familiar, but it is documented here with unprecedented detail and insight.