Byron Shafer and Richard Spady rely on cutting-edge data analyses and graph­ical presentations to provide a detailed accounting of how social characteristics have shaped core political values, which, in turn, has structured the presidential vote across the 1984–2008 elections. The study stands apart for the sheer richness and depth of its analyses of a specific data source—namely, the 1987 through 2009 Pew Values Surveys—to gain insight into the shifting contours of the American electorate. An application of item response theory to consistent sets of questions enables Shafer and Spady to produce indicators of two unob­servable attitudinal dimensions: economics and culture. These two emergent values constructs then allow them to array survey respondents in terms of percentile position. Subsequently, Shafer and Spady compute a probability distribution on each dimension based on the individual-level data. As the authors describe, these distributions may then be “cumulated, for a particular (social) group or for the nation as a whole to yield a political landscape” (p. 3). Ultimately, their approach enables them to focus on the distribution of eco­nomic values and of cultural values among partisan voters, taking into account citizens’ underlying densities in the populati