Socially constructed categories are central to sociological investigation, but their use in empirical research on culture is often limited to a role as explanatory variables in regression designs comparing differences in groups means. We argue that categories can and do structure cultural space on multiple dimensions simultaneously, and that the cohesiveness of culture within categories is under-explored in existing work. Drawing on insights from the “duality of persons and groups” and the “duality of persons and culture,” we develop the concept of Cultural Blau Space as a general tool for exploring cultural consensus. Cultural Blau Space is a multi-dimensional space defined by many measures of personal culture, and individuals are positioned within this space based on the similarity of their cultural profiles. We then explore how social groups structure a cultural space defined by political and social attitudes in two ways: within-group homogeneity and cross-group fragmentation. We find that partisan identification and educational attainment play a larger role in structuring this cultural space than ascribed characteristics such as gender, with the former increasing in homogeneity and fragmentation in recent years.