Studies of presidential veto use advance two competing theoretical perspectives: the "president-centered" approach and the "presidency-centered" approach. We assess the applicability of these approaches to gubernatorial veto activity. Our analysis of forty-eight states between 1971 and 2002 provides strong support for the institutional perspective and less support for the individual perspective. The governor's formal powers, the partisan alignment of the legislature, and the electoral cycle all contribute to veto activity. The results suggest that conflict between the legislature and the governor is a product of systematic forces and that governors who face similar institutional constraints will behave in similar ways.T he American political system distributes institutional authority to a wide array of actors. At the national level, nothing better illustrates this complex interaction than the relationship between Congress and the president. Each institution possesses prerogatives that infringe on the primary domain of the other and can foster conflict. The presidential veto power is a good example. Use of the veto is an especially important instance of direct conflict between the legislature and the chief executive and therefore ranks among the most potent powers that the chief executive has at his or her disposal. Examining the root causes of veto activity provides scholars with a deeper understanding of interbranch conflict in the American political system and sheds light on questions of institutional design, power, and decision-making authority.Presidential vetoes have received considerable scholarly attention. In attempting to explain why presidents veto legislation, political scientists advance two contrasting theoretical approaches. The first is the "president-centered" approach, which stresses the importance of "individual behavior as an influence on veto behavior" (Gilmour 2002, 199). The president-centered approach highlights the personality traits and veto strategies of individual presidents as key precipitating factors. The second theoretical perspective is the "presidency-centered" approach, which emphasizes the "institutional structures and societal conditions that constrain presidential behavior" (Shields and Huang 1997, 436). This approach emphasizes factors such as minority party opposition and the electoral cycle. Recent studies of presidential vetoes (Gilmour 2002) and of presidential behavior more generally (Hager and Sullivan 1994) provide empirical support for both the president-and presidency-centered perspectives.This article assesses the applicability of these competing perspectives in the context of the fifty American states, examining the impact of individual and institutional factors on governors' veto activity. By examining gubernatorial veto use, this article assesses the external validity of existing research on presidential veto behavior. The fifty states represent an ideal venue in which to analyze political phenomena, including the relationship between the legislature and the exec...