An unresolved question concerning the New Deal realignment is the extent to which the Democratic surge in the vote resulted from either the conversion of former Republicans or the mobilization of newly active voters. Analyzing survey data from the Literary Digest straw polls and from early Gallup polls, we find evidence supporting the conversion hypothesis. New voters in 1928, 1932 and 1936 were only slightly more Democratic in their voting behavior than were established voters. Between 1924 and 1936, the vote among established voters was extremely volatile, largely accounting for the Democratic gains. After 1936, however, vote shifts became minimal and party identification had become highly consistent with presidential voting, suggesting a crystallization of the New Deal realignment by the late 1930s rather than a gradual evolution due to generational replacement.