Douglas Martin in the New York Times:
Perhaps Professor Dahl’s best-known work was one of his earliest: “Who Governs? Democracy and Power in an American City” (1961), which examined the political workings of New Haven. In contrast to the view that power in American society was concentrated in a business elite, he depicted a multitude of groups competing for influence. “Instead of a single center of sovereign power,” he wrote, “there must be multiple centers of power, none of which is or can be wholly sovereign.”
New Haven, he argued, had experienced a historical progression from patrician rule to a more contested form of government in which political parties and candidates of different ethnic and economic backgrounds competed.
Professor Dahl initially defended pluralistic competition as inherently democratic, but in later books he theorized that powerful, politically agile minorities could thwart the will of other minorities and, indeed, majorities. He particularly worried that corporate managers could dictate the direction of their companies, often without reference to shareholders. He advocated giving outsiders, including government and interest groups like consumer representatives, a greater role in corporate governance.
He also wrote that citizens in recent years have had less influence over the political process, even as they have demanded more of it. He pointed to growing economic inequality as a threat to the political process.
More here.