This article evaluates and compares "president" and "presidency" centered explanations of presidential activity with respect to one important presidential power, the veto. Using individual bill data for nine congresses characterized by divided party government, I estimate a logistic regression model of presidential vetoes. This contrasts with previous research, which has used annual aggregate data. Using individual bill data allows controls for objectionable legislation passed by Congress and enables me to measure and compare the "propensity to veto" of different presidents. I conclude that presidential vetoes are in substantial measure caused by Congress passing objectionable bills, but that even controlling for congressional behavior, presidents exhibit strikingly different veto behavior. Ford was most prone to using the veto, and Reagan, the least. Although external factors exert great influence on the president's veto decision, the individual choices and strategies of presidents also have an important influence.A paradox of the American presidency is that this office, routinely called the most powerful on Earth, is also said by many observers to allow its incumbent relatively little autonomy. Neustadt (1960) asked whether the president was a "leader or clerk." Similarly, recent work has focused on "president" versus "presidency" centered explanations of presidential activity (Hager and Sullivan 1994;Shields and Huang 1997). Presidency-centered explanations suppose that the president is a clerk and that presidential behavior is a function of the institutional setting of the president. From this perspective, the individual attributes and idiosyncratic strategic choices of presidents have little influence, and presidents make the choices they do because of externally imposed constraints over which they have little control. The essence of the presidency-centered approach is the view "that most presidents would behave similarly in similar contexts" (Hager and Sullivan 1994, 1081). President-centered explanations suppose that the president makes choices that are not determined by outside factors and that individual attributes of the president will make a difference. According to the president-centered view, the president will have the freedom of action to im-