Final answer:
The Pluralist theory posits that a variety of organized groups influence public policy making, with political power distributed among these groups. Robert Dahl is a significant proponent of this theory, which stands in contrast to Elite theory that suggests a small group of elites dominate policy decisions.
Step-by-step explanation:
The theorist that argues that groups are the dominant influence in public policy making is known as a Pluralist. Pluralist theory emphasizes the role of organized groups in political power, competing to influence government policy. Instead of a concentrated power in the hands of a societal elite, pluralists believe that a variety of groups, including environmental advocates, unions, and business organizations, have the potential to wield power. This competition among different interests is seen as a cornerstone for democracy.
Politicians, according to pluralists, are attentive to these groups, especially those that are politically active, as a means of gaining votes and understanding the needs of ordinary people. Political theorist Robert Dahl is a seminal figure in pluralist theory, proposing that politicians strive to balance the demands of these competing groups to garner electoral support. As such, pluralism paints a more optimistic view of representation in democracy, as contrasted with elite theory, which posits that a small, privileged group primarily dictates government policy.