Since the birth of modern political science, the power of the purse has been recognized as one of the most important institutional powers through which Congress constrains presidential ambitions. Related scholarship has debated the relevance of committee composition for legislative outcomes. In this study, we examine committee influence in the context of inter-branch bargaining over appropriations. We argue that the composition of House Appropriations subcommittees constrains the president's policy success. Using comprehensive new data on presidential budget requests and congressional appropriations for the U.S. federal government from 1972 to 2021, we test the hypothesis that presidents are less successful in realizing their preferred budgetary outcomes as the relevant subcommittee is more ideologically distant from the president. The results provide strong support for this expectation. Our findings offer new evidence about how the composition of legislative committees affects policy outcomes and illustrate a mechanism through which Congress limits the president's agenda-setter advantages in budgetary politics.