During the 1960s, Harvard psychologist David McClelland focused his research and business endeavors on increasing the need for achievement in small businesspeople, with the goal of fostering economic success in the developing world. However, by the early 1970s, McClelland would focus almost entirely on developing executives' need for power in the United States. In this paper, I argue that underlying this shift was McClelland's dedication to the project of behavioral engineering and a newfound belief that training individuals in the responsible exercise of leadership and managerial power had become the most effective path to achieving his liberal political aims.