Akhil Amar is one of those scholars who rarely leaves home without a pocket-size copy of the Constitution secreted about his person (presumably safe from any “unreasonable searches and seizures”). One suspects that in stray moments–waiting for takeoff, in checkout lines at the supermarket–he likes nothing better than to whip out his copy and mull over some obscure clause. And as his newest book makes clear, he finds much there to mull. At nearly 500 pages of text and more than 100 of notes (many substantive), this is a work for the long-distance reader. Indeed, in its very length, America’s Constitution illustrates the inverse relation between the brevity of the document and its potential for voluminous exposition.

At fewer than 8,000 words, ours is a textual lightweight next to most other constitutions, including the turgid “constitutional treaty” of the European Union that French and Dutch voters recently doomed. Midway through its twenty-second decade, the Constitution is also the oldest such national document in continuous existence. American constitutionalism is distinctive in one further respect. In no other country has the practice of constitutional law and the production of constitutional scholarship become so elaborate, refined, disputatious and even cultic. Our obsession with the Constitution–its origins, evolution and especially its interpretation–has no parallel anywhere else in the world.

The literary economy and historical durability of the Constitution support this hermeneutical obsession in obvious ways. Brevity invites and indeed requires interpretation to connect the clauses, fill in the silences and search for meanings beyond the four corners of the text. The sheer fact of longevity, meanwhile, has endowed numerous clauses with interpretive histories of their own. Other provisions, like impeachment, operate as sleeper clauses, lying dormant for decades, then exploding into prominence and demanding interpretation.

One other fundamental circumstance renders our Constitution susceptible to endless explication. Ever since Alexander Hamilton proposed chartering a national bank in 1791, Americans have repeatedly had to learn that the boundary between what is political and what is constitutional is permeable. Political disputes regularly escalate into constitutional quarrels because we naturally prefer decisions to be made by those institutions that offer our side the best chance of prevailing. Moreover, our muddied schemes of federalism and separated powers mean that we can usually make a plausible case that rule-making authority resides in the institution(s) where we have the best shot.

Taken together, these conditions suggest that we will never get closure on the meaning of the Constitution. History, politics, legal precedent and the coexistence of rival interpretive theories–from the broadest versions of Ronald Dworkin’s “moral reading” of the Constitution to the narrowest form of Robert Bork’s “originalism”–all guarantee that the original document and its leading amendments will remain controvertible.

This may disturb naïve purists and enthusiastic originalists who think that the meaning of the Constitution really can and should be fixed. But it is great news for those of us who make our living writing about constitutional law, history and theory. Of course, not all of us are competent to do all three, but among those hardy few bold enough to make the attempt, Akhil Amar ranks high for ambition and enterprise.

Amar makes his intellectual home at Yale Law School, the high temple of constitutional theory. Back in the 1920s and ’30s, it was the nursery of legal realism, which treated law as a continuation of politics and policy by other means. Its transformation into a shrine of constitutional theory began with the 1962 publication of Alexander Bickel’s famous work The Least Dangerous Branch. With its careful if occasionally overwrought analysis of “the countermajoritarian dilemma”–that is, the idea that the exercise of judicial review is always problematic because it empowers politically unaccountable judges to overturn the decisions of more democratic bodies–Bickel’s book laid out the basic issue that constitutional theorists have been revolving ever since.

Amar offered his own solution to that dilemma in his last book, The Bill of Rights: Creation and Reconstruction. He argued that the authors of the Fourteenth Amendment explicitly rejected the Marshall Court’s 1833 ruling that the protections of the Bill of Rights applied only to the national government. The incorporation doctrine–the right of the federal courts to apply the Bill of Rights to the states–at the heart of the last century’s rights-oriented jurisprudence was thus historically and textually sound. And like other scholars, Amar portrayed Reconstruction as a second constitutional “founding,” committed to principles of nationhood and equality only partly imagined, much less realized, in the 1780s and ’90s.

The basic purpose of his new book, Amar suggests, is twofold: to introduce readers “both to the legal text (and its consequences) and to the political deeds that gave rise to that text.” Yet he is in fact much more the textualist than the historian, much more original and provocative when playing with the implications of constitutional language than when accounting for the motives and deeds of historical actors. Amar’s analysis of this language was originally called “a guided tour,” and that subtitle, I think, provided a better description of his method than the one it finally received. “Biography” implies life, action, movement and a sense of how the Constitution has been interpreted and applied. The reader instead is offered a thorough (though hardly comprehensive) analysis of the Preamble, all seven original Articles and its twenty-seven Amendments.

Even so, a powerful sense of American political history drives Amar’s reading of the text. If this “biography” has a dramatic structure, it lies in the tension between the Constitution’s democratic and egalitarian promise and its attendant moments of original sin and heroic redemption. Amar is progressive but not a Progressive. He rejects, that is, the old Progressive view of the Constitution as an elitist reaction to the excesses of democracy. As his opening chapter on the oft-neglected Preamble makes clear, the Framers’ confidence in “We the People”–whose assent alone made the Constitution supreme law– was genuine. That confidence was manifested both in allowing propertyless men to vote for delegates to the ratification conventions and in the large electorate, which from the beginning could choose the members of the House of Representatives.

Amar is also a nationalist. Much of the case for the Constitution rested on a “geostrategic vision” of the national interest nurtured in a realpolitik that precluded the idea that individual states retained a sovereign right to secede at pleasure. In a world where European empires could freely meddle in American affairs, such a concession would have extended an ongoing invitation to disunion.

But the price of perfecting this Union was also its original sin: the multiple ways in which the Constitution rewarded the existence of slavery as the dominant institution of the South. Like Garry Wills (in his recent book The Negro President), Amar emphasizes the “extreme viciousness” of the three-fifths clause. Not only did it provide the South with over-representation in Congress and a virtual lock on the presidency; it inspired the malapportionment of state legislatures to favor those counties where slavery was dominant, thus further reinforcing the hegemony of the slavocracy. Writing on the side of the angels and with the moral certainty of the present, Amar has little patience for historians like my late colleague Don Fehrenbacher (or myself, for that matter), who are more tolerant of–or simply more fatalistic about–the ambiguities and ironies of the past.

This vision of American history is not what distinguishes Amar from other students of the Constitution, however. It is instead his love of constitutional language that sets him apart, and his belief that real consequences flow from the choice of one term rather than another.

A good example of this is his treatment of the Twelfth Amendment, which required electors to cast distinct votes for President and Vice President, thereby preventing a recurrence of the inadvertent tie between running mates Jefferson and Burr that threw the election of 1800 into a lame duck House of Representatives controlled by the defeated Federalist Party. Amar argues that this amendment was instrumental to the formation of the two-party system that revolves, and always has, around the competition for the presidency. It certainly was helpful to improving party coordination. But one could argue just as easily that party leaders had already learned the key lessons from their experiences in 1796 as well as 1800, and that with or without a formal amendment they would have developed effective techniques to avoid a repeat of the Jefferson-Burr tie.

The abhorrent three-fifths clause evokes a similar assessment. Amar implies that it provided an incentive to continue the importation of slaves after 1789 because Southern states wanted the additional representation in Congress. But there is no evidence that it had this effect or that any slaveowner would have conditioned a purchase with so distant and personally immaterial a benefit in mind. Nor did the Upper South states that sustained the expansion of slavery into the Cotton Belt ever consider discouraging the outflow of their human chattel on similar grounds.

Neither of these reservations should detract from an appreciation of the real ingenuity that informs America’s Constitution. No scholar writing today is more sensitive to the nuances of constitutional language than Amar, and his book is full of close and thoughtful analyses of an array of clauses and terms of legal art. Readers who make it to the end of this work will be rewarded not only by Amar’s personal thanks for their diligence and (more alarming) a restatement of the major arguments they should already have absorbed but also by a new and richer understanding of the prosaic founding text we routinely worship but rarely examine.

Yet Amar’s notion of strict linguistic scrutiny, as applied to the origins of the constitutional text, is finally more an example of our obsession with the Constitution than an explanation of why its interpretation remains so fertile a source of perplexity and controversy. For all the attention that Amar bestows on the nuances of language, the life of the Constitution remains a story of movement, interpretation and even exploitation. There is much to admire in Amar’s densely packed disquisition, but it is not quite the biography it claims to be.