A game-changer when it was first published in 1961, Who Governs? remains one of the most influential political science books ever written. Dahl argues that American liberal democracy is a pluralist system in which policy is not, as is so often thought, shaped by a small group of powerful individuals. Rather, power is fragmented, with competing groups actively seeking to influence decisions and citizens indirectly shaping policy. As a case study, Dahl analyzed the decision-making process in New Haven, finding that only the mayor had power in all areas. Study of the city's highly competitive two-party system prompted Dahl to view the entire United States as Connecticut writ large.