This president's power to determine the number of appointed positions in bureaucratic agencies is an important and understudied aspect of presidential unilateral power. It can have a significant impact on policy implementation. In this article, I describe the mechanics of how presidents alter the number of political appointees and explain when presidents want to politicize. I focus on how presidents balance their competing desires for agencies to share presidential preferences but also be competent at what they do. I examine presidential staffing choices with new data on appointees in the Executive Office of the President during 1988-2004. I find some preliminary evidence that presidents add more appointees when their preferences diverge from those of an agency and that presidents are mindful of how politicization will impact agency performance. I conclude that more attention should be paid to how presidents unilaterally influence the number and depth of political appointees in the federal bureaucracy.