By reexamining the structure of political attitudes among Americans in the period 1956–72, using both the items and coding scheme as given inThe Changing American Voter (1976) by Nie and his associates and using only domestic attitude items, but including all available responses, we have found that the major type of change between the 1950s and the 1970s is not an increase in internal constraint (ideological thinking of any sort) but an increase in political attitude polarization. Further, this analysis indicates that when interitem associations are used to measure constraints present in the entire population, a major source of political attitude constraint is ignored—the constraints present within the social, political and demographic groupings within the society. The major types of attitude constraints in our society are likely to be external to the attitudes themselves. Understanding electoral outcomes will necessitate understanding the nature of electoral coalitions formed across social and political groupings.