I explain the variation in executive dominance in the executive-legislative relationship in terms of the de facto agenda-setting power of the president, which depends on legislative rules and their ability to control the governing party. I also explain how supermajoritarian legislative rules can constrain the president’s agenda-setting power. To develop a theory of executive dominance in the presidential system, I present a model that combines Krehbiel’s pivotal politics theory with Tsebelis’s veto player theory. The model simplifies various institutional veto players into the de facto agenda setter and veto players. According to the model, as the size of the core increases, it becomes more difficult for the president to achieve their agenda. I identify the core sizes of 25 different government types that emerged between 1987 and 2020 and analyze the effect of the core size on the executive agenda-setting power.
<br>Linear regression analysis yielded the finding that the executive is more likely to enact its preferred bills as the size of the core decreases.
