This book contains an extensive analysis of the voting patterns in 50 countries in the post-war era. The chapters provide some context to the emergence of the dominant parties in each country and then analyze the evolution of party support according to factors like education, income, gender, region, race/ethnicity, religion, occupation, age, and other factors --- discerning which ones are most dominant in different situations.
The collection is especially interested in the theory of the emergence of a "multi-elite" party system, where high-income voters remain allied to the right ("Merchant Right") but high-education voters move toward the left ("Brahmin Left"). Several factors are named as drivers of such an evolution: the rise of identity-based conflicts and more social as opposed to economic issues, growing inequalities in access to higher education, structural changes to the global economy resulting from neoliberalism (and the impact on social democratic parties). On the second point, the co-editors, in their survey chapter, note that "the higher educated have indeed been more left-wing than the lower educated only among voters born after World War II, while prewar generations continue in large part to vote along class lines."
Other dominant themes include immigrants and Muslim voters in Western democracies increasingly voting for parties on the left, rural areas remaining bastions of the right, and younger voters being pro-integration and more willing to vote for less dominant parties.
Given spatial constraints, each of the chapters, which unite countries with similar parameters or trajectories, is about the length of a journal article and could benefit from a full book in and of itself. But this is a great compendium for asking questions and getting some initial answers.