That the political parties have polarized in Congress is indisputable. That the electorate has followed suit, on the other hand, is one of the liveliest debates in American politics. With Authoritarianism and Polarization in American Politics, Marc J. Hetherington and Jonathan D. Weiler have greatly contributed to this debate. Getting beyond the “is there or isn't there?” questions, they provide a microlevel foundation that dynamically shows how at times polarization in the public is muted and at other times is raging. Authoritarianism, they argue, has increasingly organized American public opinion over the last 40 years. Because of this provocative argument and because of the data that the authors bring to bear on the subject, anyone interested in American politics should read this book.

Hetherington and Weiler recognize that by employing the “authoritarianism” concept, they are entering a minefield of scholarly debates about the concept. Instead of directly engaging in those debates by dwelling on a precise definition of the term, they ascribe beliefs and actions not only of authoritarians but also of nonauthoritarians. This strategy is useful especially for readers who do not have much at stake in what authoritarianism means and in how it is measured. Abstractly, they argue “that those who score high in authoritarianism have (1) a greater need for order and, conversely, less tolerance for confusion or ambiguity, and (2) a propensity to rely on established authorities to provide that order” (p. 34). More concretely, authoritarianism is the “connective tissue” between “race, morals, and hawkishness” (p. 29). Although defining authoritaranism by describing the actions and beliefs it motivates is illuminating, the authors are especially thoughtful in discussing nonauthoritarians. Not wanting to simply define nonauthoritarians as those who are not authoritarian, they describe them as holding a strong “notion of fairness … an aversion to prejudicial thinking; valuing personal autonomy over social conformity; an aversion to judgments that make them relativistic; and a tendency to be broadly opinionated” (p. 43).

Hetherington and Weiler demonstrate not only how authoritarianism structures individuals' current worldviews but also how it has come to be a predominant component of individuals' worldviews over the last 40 years. The major debates of the New Deal, race relations, feminism, civil liberties, and diplomacy can all be understood through the authoritarian lens inasmuch as each of these debates can be portrayed as respecting order versus seeking justice. Their thoughtful argument is substantiated by adept, thoughtful, and compelling statistical analyses.

As it turns out, nonauthoritarians provide the primary explanation for the current polarization in the American electorate. As nonauthoritarians are threatened, they act more like authoritarians. As that threat recedes, they act less like authoritarians. According to Hetherington and Weiler, as the September 11 threat becomes a more distant memory, the nonauthoritarians' worldview is increasingly distinct from the authoritarians' worldview. As the ripples from 9/11 continue to fade, the American opinion on leaders, issues, and priorities has become increasingly polarized.

Throughout most of the book, Hetherington and Weiler use opinion on child rearing to measure authoritarianism: “[T]hose who value ‘respect for elders,’ ‘obedience,’ ‘good manners,’ and ‘being well behaved’ score at the maximum of the [authoritarian] scale. Those who value ‘independence,’ ‘self-reliance,’ ‘curiosity,’ and ‘being considerate’ score at the minimum” (p. 48). They center their analysis on attitudes toward gay rights and policies to avert terrorism, arguing that authoritarians are more likely to oppose gay rights (because of their support for tradition and social stability) and support strict policies to avert terrorism (because of their support for personal safety). Hetherington and Weiler show how these issues have taken up an increasingly large share of the marketplace of political discourse. Furthermore, they show how opinions on one of these issues increasingly constrain an individual's opinion on related issues.

Authoritarianism, as it so happens, also structures opinions on immigration reform. In addition to being closely linked to an individual's views on gay rights and terrorism, immigration has also become an increasingly important topic as the electorate has polarized. Respondents' adherence to authoritarianism matters in understanding their beliefs on immigration reform above and beyond even their ideology, party identification, and race.

Authoritarianism can explain not only the divide between Democrats and Republicans but also the divide within Democrats in the 2008 presidential primaries. As the contest wore on, the divide between the supporters of Hillary Clinton and Barack Obama were increasingly defined by their attitudes over authoritarianism. That Obama ultimately won the contest in a party dominated by nonauthoritarians should not be surprising. That Obama was able to win the general election contest by sufficiently capturing Clinton's authoritarian voters is a puzzle that Hetherington and Weiner do not explain. That he was able to do so as the economy was on the brink of collapse—a condition that most might assume is quite threatening—also remains unexplained.

While I encourage all those interested in American politics to read this book, I have two relatively minor criticisms—one structural and the other conceptual. First, structurally, the last third of the book reads a little bit like “and then immigration,” “and then the 2008 primary contest,” “and then the 2008 presidential contests.” Whereas the concept of authoritarianism and the issues of gay rights and terrorism were nicely woven together in the first two-thirds of the book, the latter chapters appear mostly as add-ons to appease reviewers or to take advantage of current events. This criticism is not to suggest that immigration and the 2008 election should not have been analyzed, just that these analyses could have been as integrated into the argument as the issues surrounding homosexuality and terrorism.

I think the most provocative part of the book is the analysis on nonauthoritarians and how, in the absence of an overwhelming threat, their opinions become increasingly different from those of authoritarians. This nugget of analysis gets lost when the authors discuss the current state of polarization in the electorate. Hetherington and Weiler are too eager to conclude that the American electorate is becoming hopelessly polarized. While that conclusion is fair under the current set of circumstances, circumstances could change quickly. What their analysis shows quite convincingly is three things: 1) Authoritarianism has increasingly structured American public opinion; 2) in the absence of threat, authoritarians think increasingly differently about the world than do nonauthoritarians; and 3) nonauthoritarians do not currently perceive much threat. For polarization in the electorate to continue, the status quo would have to persist. If nonauthoritarians start perceiving a bigger threat, polarization could quickly give way to consensus. As such, the first two statements summarizing their argument are likely to persist. The last one, however, is highly contingent and much less certain.

These small quibbles notwithstanding, the authors have offered an argument and compelling evidence that will greatly shape the polarization-in-the-electorate debate, which, regrettably, too frequently reduces to arguments about how the data are represented. The magic of their argument is that they have a dynamic theory to explain a dynamic process. Too frequently the polarization debate has been mired in static theories explaining dynamic processes. Hetherington and Weiler have surmounted this challenge and reshaped the debate on polarization because of it.