Our observations of the political world are filled with examples of presidents who move policy with the stroke of a pen. The executive order, one of several tools available to presidents, is a primary example of unilateral governance wherein presidents change policy, create programs, and reorganize the government without a single vote in Congress. In political science, we study these demonstrations of executive action by paying attention to a subgroup of so-called “significant” executive orders, those with policy implications that garner the attention of other institutional actors (including the press). However, this broad category still covers a wide range of salience that muddles our understanding of how and when presidents use unilateral action. In the dissertation, I identify an even narrower set of “critical” executive orders that represent the most impactful unilateral actions of presidents. Focusing on these orders, I study the political context in which they are issued so that we can better understand the dynamics associated with greater presidential prolificacy in their unilateral governance. I use count models to identify the political factors that shape a president’s ability to issue such orders and find that divided government, polarization, presidential approval, the economy, war, and other timing variables all provide clues to the president on whether he or she has a favorable environment for issuing such orders. I also find a difference in the factors that influence the issuance of critical executive orders when broken down by domestic versus foreign and defense-related policies. When these factors are associated with lower numbers of critical executive orders, I argue that presidents are effectively constrained because they recognize that their circumstances do not as easily lend themselves to unilateral action. Recognizing that executive orders are just one of many unilateral tools available to presidents, I close with discussion about the need to identify significant subsets of these other tools and aggregate them to create a fuller picture of unilateral governance in the American system.