In this chapter, I argue that Brazilian presidentialism has been affected by the combination of three institutional features that Shugart and I (Chapter 1 and the Conclusion, this volume) discuss and one that we do not. First, presidents have had sweeping constitutional powers, especially under the 1988 constitution. The 1988 constitution gives presidents exceptionally strong proactive and some significant reactive powers; the 1946 constitution gave presidents strong reactive powers. Second, a highly fragmented party system has also affected Brazilian presidentialism. With a highly fragmented party system, presidents are usually in a situation of informal coalition government or (exceptionally) of minority presidentialism. Because their parties control a minority of seats, presidents need to build cross-party coalitions to implement most major policies. Third, comparatively undisciplined catchall parties make it difficult for the president to rely exclusively on party channels of support. When presidents are popular, politicians of all stripes and colors support them, but when they lose favor, they often have difficulty winning support for their projects. Defections in hard times make it difficult for presidents to implement major reforms. Finally, federalism has also shaped the functioning of Brazilian presidentialism. The logic of politicians and parties in Brazil is deeply engrained with robust federalism, which reinforces the dispersion of power created by the highly fragmented party system. With this institutional combination, presidents have sweeping consti tutional powers (especially under the 1988 constitution) but weak partisan powers.