Alexander Bickel, the great scholar of the Supreme Court, famously called the power of judicial review “counter-majoritarian.” Nowhere does the Constitution explicitly grant the Supreme Court the power to declare law unconstitutional. More to the point, the practice is hard to square with the idea of democratic governance. After all, democracies are supposed to vest law-making power in legislative majorities that are electorally accountable to the people. The Supreme Court, by contrast, answers to no electorate, and its members, once nominated by the president and confirmed by the Senate, enjoy life tenure. Why, then, do we permit this unelected elite to overturn and render void the laws framed by the democratic branches of government? Perhaps the most familiar answer to this question turns on the distinction between majoritarian preference and minority rights. While democratic institutions are well equipped to protect and promote the interests of majorities, they function less perfectly when it comes to defending the rights of minorities. This is where the Supreme Court comes in. Insulated from the rough-and-tumble of electoral politics, the Court is institutionally designed to defend minorities against tyrannical majorities. Judicial review permits the Court to strike down laws that violate the fundamental rights-particularly those of minorities-enshrined in the Constitution. A new book by Jeffrey Rosen, legal affairs writer for the New Republic, sternly challenges this conventional explanation. In a nod to Bickel’s classic study, The Least Dangerous Branch, Rosen has called his book The Most Democratic Branch: How the Courts Serve America, a title that reveals much about his project. According to Rosen, the Supreme Court has rarely served as the great bulwark against majoritarian excess. Through most of its history, the Court has functioned as a “reliable representative of the constitutional views of the American people.” Judicial review, he insists, has done little to protect the contested rights of vulnerable minorities; mostly it has been used to strike down “outlier” laws “dramatically out of line with a clear national consensus”-such as the Connecticut ban against contraceptives overturned in the famous Griswold decision (1965). And this, he insists, is as it should be. Rosen develops this argument in a compact, elegantly argued, and highly readable survey of American constitutional history. In a scant two hundred pages, he covers everything from John Marshall’s canonical decisions in Marbury v. Madison and McCulloch v. Maryland to recent holdings such as Lawrence v. Texas, in which the Court struck down a Texas statute criminalizing homosexual sodomy. It is to Rosen’s credit that this highly compressed history seems neither hurried nor superficial, but instead manages to inform the newcomer and challenge the expert. More controversial are the conclusions that Rosen teases from his history. When the Court behaves in a “unilateralist” fashion-when it strikes down laws that are still being “actively and intensely contested by a majority of the American people”-it flirts with disaster, he argues. The two clearest examples of such unilateralism remain the Dred Scott case (1857), in which the Court calamitously declared the Missouri Compromise unconstitutional, and Roe v. Wade, the 1973 decision that struck down a Texas statute criminalizing abortion. In both cases, Rosen claims, the Court imposed its own constitutional vision in the face of widespread disagreement in both Congress and the public itself. In so doing, the Court provoked intense political backlashes and invited challenges to its larger institutional legitimacy. The Court is far better off, Rosen insists, when it behaves more humbly and with greater restraint, enforcing “only those values that national majorities are willing to recognize as fundamental.” At first glance, this looks like yet another tired attack on “judicial activism.” But it differs importantly from the arguments of pundits on both the Right and Left in its repudiation of the value of constitutional theory. Students of the Constitution are relentlessly schooled in the importance of theory: in the absence of a clear theory of constitutional meaning, it is argued, judges will simply read their own personal values onto the Constitution-the very essence of activist judicial practice. Rosen emphatically disagrees. Theories such as “originalism”-the idea that the Constitution should be interpreted in terms of the original understandings of its clauses-fail to constrain interpretive freedom and often license the most extreme gestures of judicial activism. Against the claims of theory, Rosen defends a modest jurisprudence in which the Court should be as concerned with assessing the temper of the nation as it is with reading the text of the Constitution. Yet however refreshing, this approach is not without its problems. First, Rosen must conclude, however reluctantly, that some of the Court’s most disreputable decisions were properly decided, at least at the time of their holding. For example, he can find no obvious fault with Plessy v. Ferguson (1896), in which the Court, deferring to majoritarian sentiment, enshrined the separate-but-equal formula, the constitutional basis for over half a century of state-sponsored segregation. Rosen struggles to justify this conclusion by arguing that had the Court decided otherwise, its decision probably would have been ineffective anyway, but this justification by counterfactual hypothesis rings hollow. Conversely, Rosen must conclude that many of the Court’s greatest decisions were in fact nothing more than modest consolidations of larger changes in public opinion. Rosen rejects the conventional wisdom on Brown v. Board of Education (1954), that the Court dragged a reluctant nation to a new understanding of civil rights, and instead claims that the Court largely solidified a change in public attitudes about race that predated the “landmark” decision. (Rosen does acknowledge a limited power of the Court to spearhead political change.) He rests this argument, however, on the slender results of polls taken in the wake of Brown, and, in so doing, trivializes the courageousness of the decision, which required great will, vision, and resolve on the part of the justices. Rosen’s revisionist reading of Brown suggests a final problem with his argument. He defends judicial review when exercised in modest support of majoritarian sentiment, but he never tells us how the Court is to measure national political belief. Is the Court to follow public-opinion surveys? Should the justices hire pollsters instead of clerks? If this sounds preposterous, it is precisely because, as Bickel long ago observed, the Court is designed to be insulated from public opinion. How, then, is an institution uniquely ill-equipped to measure majority belief supposed to use this uncertain standard as a guide to decision making? That Rosen fails satisfactorily to answer this question suggests that his book should be read for the many pleasures of his smart, elegant, and provocative exposition and not for the definitiveness of his solutions.