The topic of presidential-congressional relations is well studied, with scholars identifying party control as a strong predictor of presidential success in Congress. Although the research recognizes the importance of policy variation to explaining political processes, few have examined its impact on presidential success in Congress. This article holds that policy scope is important to explaining presidential success in Congress in that different policies engender different levels of conflict and participation in the legislative process. Using data on individual policy proposals from 1949 to 2006, I demonstrate that the policy scope of the president's legislative agenda not only affects the likelihood of presidential success, it also conditions the impact of expected effects on presidential success.