Final answer:
C. Wright Mills is the sociologist who identified the existence of a power elite in society, a small group of influential people controlling key societal domains. His work was further elaborated on by G. William Domhoff, who explored the subcultural aspects of this elite group.
Step-by-step explanation:
The American sociologist who theorized about the existence of a power elite in society is C. Wright Mills. In his seminal work The Power Elite (1956), Mills describes a small ruling group comprising wealthy executives, politicians, celebrities, and military leaders. These individuals have access to national and global resources, occupying powerful positions that allow them to influence major decisions and policies that shape society. Mills' analysis extends from Karl Marx's ideas, but he provides a more contemporary and specific look at the interwoven interests of the top-tier societal leaders. Additionally, G. William Domhoff's research, particularly in Who Rules America?, builds upon Mills' work, suggesting that the power elite operate within a subculture characterized by exclusive social clubs, prestigious education, and luxury destinations, reinforcing their own social patterns and maintaining their wealth and influence.