Political movements in a crisis period encompass both ideology and economic demands. Their proposals look to changes in the wider society and are in this sense broader than the proposals of interest groups. Their constituents, in deprived positions in society, require more large-scale changes. Moreover, in the disrupted position in which people find themselves during a crisis, they require some general explanation of the relation between narrow economic demands and their general welfare. Deprived of power, they are not likely to be motivated to act to change their situation by appeals to practical self-interest alone. Because the obstacles to surmount are so great, such appeals seem illusory and in fact often are. Therefore, some emotional appeals are essential; protest movements have crusade characteristics. The movements of farmers in the 1890's, workers in the 1930's, and Negroes in the 1960's have all been crusades. The emotional appeals of these movements transcend rationality defined in terms of Benthamite narrow self-interest. But narrow groups are specifically irrational in a crisis period because their methods can succeed neither in achieving results nor in attracting adherents.
To treat mass movements in pluralist terms is to make them a priori irrational. When they are viewed as responses to social crises, a different picture emerges. Populism must