It was the summer of 1832, and the two great Whig senators, Henry Clay and Daniel Webster, had come across a brilliant plan to embarrass and damage the Democratic president, Andrew Jackson, just before the election. The Second Bank of the United States, hated by agrarians and Jacksonians, but much prized by industrialists and National Republicans, was to be rechartered in four years. Nicholas Biddle, the president of the bank, was considering an early recharter. If Congress passed legislation rechartering the Bank before the election, Clay and Webster figured, Jackson would be faced with a fait accompli and would be forced to renege on one of his major campaign promises.

To everyone's shock, Jackson vetoed the bill. Accompanying the veto was a signing statement, which stated boldly that Jackson was not merely vetoing the bill because he believed it to be unconstitutional, but also because he believed it to be bad policy. This was a sea change: For forty years, the American presidency had treated the veto as a judgment on the constitutionality of pending legislation and nothing more. Now Jackson had transformed the presidential office into an institution with the capacity to ratify the policy agendas of Congress. There was outrage in Congress; Webster was apoplectic; cartoons were passed around of "King Andrew I." And Jackson won reelection against Clay by an enormous margin.

One of the great pleasures of reading Harold H. Bruff's Untrodden Ground: How Presidents Interpret the Constitution is the speculation it allows on the historical contingency behind stories like this. There was no historical rule necessitating that the president develop into the office it is now: perhaps, if Jackson had acted differently, the presidential veto would have remained reserved for qualms about constitutionality. If Washington had listened to Hamilton's Federalist 77, the Senate would be able to advise and consent on executive removal of cabinet officers. Astonishingly, as late as William Henry Harrison's election in 1840, the Whigs "envisioned a single-term president who would rarely use the veto power, would defer to the Senate regarding patronage, and would even allow the cabinet to determine administration policy by majority vote." But Harrison died almost immediately and his vice-president John Tyler rebuffed the Whig notion of the presidency. Bruff takes us through the fateful expansion and definition of executive power by America's great (and less great) presidents with compelling narrative, accuracy, and general evenhandedness—although conservatives will have quibbles here and there with his generally liberal perspective on policy.

But the conclusions Bruff comes to are more suspect than his careful historical narrative. Bruff takes the lesson of contingency—that executive power was never firmly fixed and depends very much on a historical set of norms built up from Washington to Jefferson to Lincoln to Reagan—and fashions it into a legal philosophy.

Contra the originalism of Scalia and other conservatives, Bruff argues that the history of executive interpretation demonstrates that the Constitution should be interpreted flexibly, that the oath of office merely requires presidents to operate "within the boundaries of the Constitution as its understanding has come down, with the modifications that he or she can make through personal effort that is accepted by the people." The argument, as Bruff makes it, is that the executive defines its role in response to the challenges and stresses of the time. If a particular presidential interpretation of his constitutional role is "accepted by the people," it makes its way into the historical canon and is ready to be invoked by some future presidency; the set of norms that thus develops serves as the constitutional orbit for the executive branch. The problem with this argument is that much of the Constitution was written with the intention of delegating very specific powers and responsibilities. To allow these to be reinterpreted beyond their original meanings simply by popular consensus is to yield whole fields of power to a potential demagogue.

For instance, the faithful execution clause stipulates simply that the president must "take care that the laws be faithfully executed." The simple meaning of the clause is clear: The presidency should work in good faith to advance with the executive apparatus the priorities passed by law into Congress. But many presidents have historically interpreted it as giving such broad mandates as "securing life and property" or other constitutional rights whenever they're deemed under threat. Grover Cleveland invoked it to put down the Pullman strike in southern Chicago and Harry Truman used it to preserve federal order during labor unrest seventy years later. Given that there are already provisions in the Constitution that regulate executive management of insurrection, this type of interpretation seems little more than a broad mandate for presidential authority at the expense of the checks and balances deliberately installed in the Constitution.

Justified and unjustified invocations of the clause, given this interpretation, come down to policy preferences, not constitutional argumentation. So for Bruff, Jackson's Indian removal represents a failure of faithful execution, as does Truman's tolerance of McCarthyism in the executive branch and, incredibly, George H.W. Bush's pardoning of officials involved in the Iran-Contra scandal, which relied squarely on long-existing executive powers and had little to do with any "laws" whatsoever. On the other hand, FDR's declaration of a bank holiday without any congressional authorization whatsoever is accepted as an "aggressive" use of his faithful execution power. If these sorts of interpretations are allowable, the faithful execution clause imposes no constraints at all. It shouldn't be particularly surprising that Bruff fails to take issue with Obama's executive orders allowing for the non-enforcement of congressional laws on immigration. If faithful execution means everything, it means nothing.

Bruff does a good job demonstrating that the role of the presidency has changed dramatically over the last two hundred odd years, and that many changes have arisen as innovative responses to new realities. But, even though Bruff is quick to note that all executive interpretations have to have some backing in the text, his theory of interpretation would yield vast and largely unconstrained fields of power to an unscrupulous president. Particularly a president with populist tendencies. Particularly in an era with a weak legislative branch. As the era of Clinton or Trump approaches, it should be clear how dangerous this theory is.

Max Bloom is an intern at THE WEEKLY STANDARD.