This chapter provides an introduction to the meaning of issue intensity and frustrated majorities through review of the existing theory and evidence of political science. I suggest that while theories of trade politics, bureacracy, legislative behavior, and political parties have explicitly or implicitly considered the consequences of varying issue intensity, the political science of elections has given it short attention. I show how the political science of the electoral connection complicates many existing explanations for frustrated majorities and suggest that adding issue intensity to the electoral connection provides an improved explanation.

In this chapter I consider the consequences for political participation where an institutional change opens a new avenue of political action. In 2017 the City of Seattle, Washington implemented a program of Democracy Vouchers as publicly-funded campaign contributions for its citizens in city elections. I show that the institution of Democracy Vouchers has different empirical implications for three existing theories of political action than for intensity theory and present a research design and data to evaluate the different implications.

In this concluding chapter I summarize the theoretical and empirical results, provide a recipe to apply intensity theory in new settings, revisit and speculate about model assumptions, suggest five key implications for our understanding of representation, electoral competition, and political action, discuss the potential importance of issue intensity for the dynamics of policy change, and offer concluding thoughts.

In this chapter I walk through the how and why of a theory of issue intensity and electoral competition and build the basics of the mathematical model used to explore intensity theory. I lay out six foundational assumptions of the model drawn from existing theories of elections in political science or political economy. The assumptions rule out current explanations for frustrated majorities so that I can show that the combination of issue intensity and electoral competition alone can cause frustrated majorities. I show how costly political action becomes an important part of the story when candidates cannot perfectly observe the issue intensity of voters. I then present a simple mathematical model with numerical examples to provide intuition for analysis in subsequent chapters.

This chapter explores two case histories where American politicians appear to have sided with intense minorities over less-intense majorities. First, I present the case of federal funding for stem cell research in the early 2000s. I find evidence that majorities supported allocating federal health research funds toward research using embryonic stem cells yet federal policy remained stringent for most of the decade. Second, I present the case of firearm regulation following the mass shooting at Sandy Hook Elementary School in 2012. Although large majorities indicated support for new regulation of firearms, no new regulations passed Congress. An intense minority appears to have used costly political action to communicate their strong opposition to new regulations.

In this chapter I consider the consequences for political participation where an institutional change closes one avenue of political action. Since the early 1990s, multiple American states have ended closed party primary elections, rules that restricted participation to voters previously registered with the political party. I show that if participating in closed primaries is costly to voters, reforms to liberalize access to primary elections have different empirical implications for existing theories of political action than for intensity theory. I present a difference-in-differences research design and data to evaluate the different implications.