Robert Alan Dahl (; December 17, 1915 – February 5, 2014) was an American political theorist and Sterling Professor of Political Science at Yale University. . He established the pluralist theory of democracy—in which political outcomes are enacted through competitive, if unequal, interest groups—and introduced "polyarchy" as a descriptor of actual democratic governance. An originator of "empirical theory" and known for advancing behavioralist characterizations of political power, Dahl's research focused on the nature of decision making in actual institutions, such as American cities.
https://en.wikipedia.org/wiki/Robert_Dahl