The period of greatest socialist strength in the United States, the second decade of the twentieth century, coincided with the final decade of a great wave of immigration. This phenomenon has attracted the attention both of scholars seeking to understand the basis of support for the American Socialist party and of those seeking to address the more general question of the sources of immigrant radicalism (Bodnar 1985; Lipset 1977). Both perspectives pose a basic empirical question: What role did ethnicity play in support for the Socialist party, or, more specifically, which immigrant groups supported the party and which groups opposed it?
The attempt to answer this question has spawned a vast scholarship on the part of historians and social scientists, but a definitive answer remains elusive. Part of the reason for this is that we lack sufficiently detailed and disaggregated data on the political orientations and activities of immigrants themselves. The smallest units of electoral return are at the ward or county level, and information at this aggregate level can never allow us to draw conclusions about individual behavior with any certainty. But it also seems to be the case that the analysis of currently available data has not been taken as far as possible. Previous research has explored the relationship between ethnicity and socialism by examining particular immigrant groups in individual states, cities, or towns (e.g., Critchlow 1986; Gorenstein 1961; Leinenweber 1981; Lorence 1982; Miller 1975; Wolfle and Hodge 1983). Such case studies provide invaluable accounts of the diversity of immigrant politics, but they do not provide a reliable basis for generalization. In this article we take a step back from the wealth of illustrative analysis and try to gain a broader, more systematic, overview of immigrant support for socialism across a wide range of contexts by examining voting among eight immigrant groups—Germans, English, Finns, Irish, Italians, Norwegians, Russians, and Swedes—in the presidential elections of 1912 and 1920, elections in which the American Socialist party received its highest levels of support.