The presidential power of unilateral action

In this article we highlight a formal basis for presidential power that has gone largely unappreciated to this point, but has become so pivotal to presidential leadership and so central to an understanding of presidential power that it virtually defines what is distinctively modern about the modern presidency. This is the president's formal capacity to act unilaterally and thus to make law on his own. Our central purpose is to set out a theory of this aspect of presidential power. We argue that the president's powers of unilateral action are a force in American politics precisely because they are not specified in the Constitution. They derive their strength and resilience from the ambiguity of the contract. We also argue that presidents have incentives to push this ambiguity relentlessly to expand their own powers - and that, for reasons rooted in the nature of their institutions, neither Congress nor the courts are likely to stop them. We are currently in the midst of a research project to collect comprehensive data for testing this theory - data on what presidents have done, as well as on how Congress and the courts have responded. Here we provide a brief history of unilateral action, with special attention to the themes of our theoretical argument. We also make use of some early data to emerge from our project. For now it appears that the theory is well supported by the available evidence. This is a work in progress, however, and more is clearly needed before definitive conclusions can be justified.