This exciting book foregrounds for the first time a powerful influence on the decisions of the Supreme Court justices—that of the elite legal networks. Their influence comes from social psychological pressure, with the justices taking cues from them and seeking their approval; it is thus not a matter of deliberate choice, but of unconscious psychology. Neal Devins and Lawrence Baum argue that this elite aspect of the external environment matters more than other external influences or policy goals.

One aim of the book is to “document and explain the widely noticed fact that the polarization of the parties has spilled over to Supreme Court appointments,” with Democrats appointing liberals and Republicans conservatives. Presidential selection—and the seriousness with which both sides now take it—is the primary reason for polarization (p. 13). The rise of conservative legal networks is the second major force.

The book’s main goal is to demonstrate the influence of elite networks on the makeup of the Supreme Court and on the justices once seated. What of the standard claims that the justices’ own policy preferences simply, or not so simply, drive their behavior? The authors point out that the justices have little personally at stake in policy, but can obtain psychological rewards by making elites happy (of course, this assumes that said elites have policy goals themselves). The authors also present an elaborate and potentially persuasive critique of claims about generic public influences on the Court (pp. 39ff).

The structure of the book is straightforward. Chapter 2 makes the core arguments about social psychology and the influence of elites. Chapter 3 gives some history and works through the nature of and changes in polarization over time. Chapter 4 develops these concepts, situating the Court in a polarized world, and Chapter 5 concludes.

The authors give a fresh new reading of Court history, explaining why justices who were expected to be more conservative positioned themselves or drifted to the left (from the 1950s to the 1980s) and why current justices are so very conservative, attributing this to the rising power of the conservative legal network. In contrast, the “liberal legal network is much larger than the conservative legal network, and, consequently, Democratic presidents are less likely to be captured by a subset within it” (p. 129). Some might find the history too “just-so,” in which the pre-New Deal justices followed a largely conservative elite to oppose regulation and then the New Deal justices curried favor with later elites who preferred regulation. Similarly, elites were previously split on civil liberties, but then moved toward favoring civil rights, pushing the justices, including notable Republican appointees, leftward on such issues. To be sure, if everyone is trending, then we do not need to see justices as followers. Others will see as overstated the claims of homogeneity in opinion of the elites in the 1970s and 1980s.

This history is written with an eye toward two themes and three related points. The two themes are elite influence and the new phenomenon of perfect partisan sorting into ideological camps. The main points are as follows: (1) only those who are tied to ideologically oriented subsets of elites get on the Court now; (2) pressures from the elected branches of government or the public do not matter, compared to elite pressures; and (3) there are norms that set judicial politics apart, such as collegiality and legal thinking. The authors argue that the justices embrace such norms because they care about their reputation among elites (p. 11), so this brings us back to the second point.

Polarization is not completely new. Indeed, modern conflict on the Supreme Court lacks some of the drama of the past. Consider the well-publicized squabbling of the New Deal cohort (Jackson, Black, and Douglas being key figures in such stories), or the impeachment threats and other legal threats of the 1960s and 1970s (Warren, Fortas, and Douglas again), or the flaring tempers and personal conflicts behind the scenes from various years (McReynolds, Black, White, Frankfurter, and of course Douglas again). But what is new in the current polarization is something that is completely different from the past: for the first time (at least in the vaguely modern era) we have a completely clean sorting of the Court, with the partisan blocs and ideological blocs perfectly aligned (powerfully demonstrated on pp. 72–73 and elsewhere). Republican dominance of the Court did not use to mean conservative dominance, but now the two go hand in hand. There is an unstated irony in all this: the current justices come from the legal system and have stronger ties to legal interest groups and thus their polarization has followed, whereas in earlier times justices often came from the political arena and yet were less polarized.

The authors lay down a bold marker, wanting the theory of elite influence to explain the partisan divide itself: “This book tells the story of how party polarization turned the Supreme Court into a Court in which ideological divisions follow party lines” (p. 2). The elite story they tell certainly does connect nicely to the boldness of the partisan divide, even if does not necessarily fully explain the divide itself.

This book’s explicit argument is a carefully reasoned and important contribution to the scholarly literature. I would not judge the book by dramatic flourishes such as this statement: “Elite polarization explains the partisan division on the modern Supreme Court” (p. 145). The contributions are notable even without that finding being nailed down tightly. In contrast, the authors do not claim sufficient credit for studying a difficult area: where (subconscious) preferences or positions originate.

This book will be of interest both to Supreme Court scholars and to a broad range of lay readers. It could fruitfully be discussed in undergraduate classes, where the students will be familiar with peer pressure dynamics. And it would provide graduate students with jumping-off points for diverse projects.

Just as Devins and Baum were inspired by disagreeing with Barry Friedman’s Will of the People (2010), this book may inspire future research on themes such as the following:

• • Magnitude. How many votes do the pressures of such external interest groups actually affect? Do they also affect legal doctrine or only votes? Or do they work more through the fun stabs of the pen for which Scalia was known?

• • Partisan sorting. What are the other implications of the perfect partisan/ideological sorting the book describes? Or, flipping the baseline, how did the cross-cutting blocs previously affect behavior? How does strict partisan sorting affect lower courts and hierarchical politics?

• • Inequality. What are the implications of the book’s argument for inequality, given that the interests of many will not be directly represented in key elite circles?

• • Partisan differences. Republicans have foregrounded ideology, whereas Democrats have pursued other objectives such as diversity (p. xiii and elsewhere). Will this change?

• • Other courts. Because lower court judges do not have the automatic cachet of being Justices, would they be perhaps even more likely to curry favor and applause?

• • Moderate elites. Can elites moderate rather than polarize? Perhaps the middle is no longer there to play to, but I am not sure the evidence is sufficiently strong to make that claim.

• • Research design and identification. There is naturally no decisive test of the key hypotheses, but rather a broad array of evidence that supports them. Can we find ways to identify more precisely, in a research design sense, the causal effects highlighted in the book? Almost every decision can be praised by some contingent, some for purity, some for independence. Even when elites tilt strongly, there are opposing groups. When Justice Scalia said Lawrence v. Texas happened because the legal profession “signed on to the so-called homosexual agenda,” he was playing to one constituency, just as voting against Scalia played to another. Maybe Chief Justice Roberts did not go as far as others would have in striking down the Affordable Care Act because he was pleasing an audience, or because he was an institutionalist (p. xii), or because he wanted to avoid doing so on purely partisan lines (p. xvi), or because his preferences were not to do so, or because of public opinion, or so on. There are many possibilities, complicating identification of causal effects in this research setting. Variation might be more testable. Some justices came from more elite backgrounds, but even those Justices from non-elite backgrounds found elite connections early (e.g., Thomas and Sotomayor; p. 11). Some will care more about esteem and others less. Although all receive a high level of respect in some way, their reputations vary considerably (p. 23). Yet “none of us got enough love in our childhood,” as Chicago’s Roxie says eight times a week.

Like many good books, this one raises as many questions as it tackles.