The stability of party affiliations and the existence of class cleavages between the parties are taken for granted as two fundamental features of American political behavior. But an examination of individual voter behavior shows that these features are historically contingent, emerging out of the New Deal realignment of the 1930's. I examine the impact of the Great Depression on party identification using a new dataset, the California Great Registers, voter lists documenting every voter registration in California for the first half of the twentieth century, matched to individual-level Census records covering the same period. In California, the New Deal realignment was brief, lasting from 1930 to 1936; 15 percent of voters switched from the Democratic party to the GOP every 2 years during the period. Pre-realignment, political affiliation was fluid: voters moved back and forth between the parties. But after six years of partisan upheaval, party membership stabilized, with fewer than 2.5\% of voters changing their party affiliation thereafter, leading to the partisan stability observed in the 1950's by the authors of The American Voter. Before this, party and class were uncorrelated, all income groups were about 20\% Democratic. The realignment forged a Democratic-majority among blue-collar workers, while two-thirds of white-collar workers remained with the GOP.
Brad Spahn is a Ph.D. Candidate with an interest in American politics and political methodology.