From Truman to Clinton presidents have aggressively tried to expand their control over national government. In the process, they have vastly enlarged their White House staffs and politicized the federal bureaucracy with thousands of appointees in key administrative positions. Thomas Weko argues that the Presidential Personnel Office (PPO), charged with screening and recommending such appointees, both exemplifies and helps explain the enormous growth of presidential power since World War II.

Originally conceived as a small advisory group within the White House Office, the PPO has grown...