In its day, this was a fine work on ideology and politics. The thesis is that to define the range of ideological variation from liberal to conservative was too simply. The authors, using public opinion data, developed a four fold typology. The horizontal rows were labelled "For expansion of personal freedoms" versus "Against expansion of personal freedoms." The vertical columns were labelled "For government intervention in economic affairs" versus "Against government intervention in economic affairs." Given that, four separate ideological positions emerge: Liberal (for expansion of personal freedoms and for government intervention in economic affairs), Libertarian (for expansion of personal freedom and against government intervention in economic affairs), Populist (against expansion of personal freedoms and for government intervention in the economy), Conservative (against expanding freedoms and against government intervention in economic affairs).
Data from 1972, 1976, and 1980 show the following: percentage of the public who were liberal ranged from 17% in 1972 to 24% in 1980; Populists began at 30% in 1972 and stood at 26% in 1980; Conservative percentage of the population ran from 18% in 1972 to 16.5% in 1980. Libertarians? 9% in 1972 and 18% in 1980--essentially doubling its share of the population.
The book goes on to explore various aspects of the ideological divergences in the public.