One theory of American democracy, pluralist theory, states that shared interest groups, like the NRA (National Rifle Association), influence public policy by pressing their concerns through organized efforts. For example, in the 1950s, civil rights groups were able to win the action they were seeking from the courts.
Pluralists are generally optimistic that the public interest will prevail in the making of public policy through the process of bargaining and compromise. They believe that rather than there being a majority rule, it should be called a group of minorities working together. Alexis de Tocqueville called us a "nation of joiners", meaning we are all part of groups, and he cited associated activities as one of the crucial reasons for the success of American democracy.
Elite and Class Theory
Critics of pluralism believe it's too optimistic. They say that by arguing that every group can get a piece of the pie, they say that pluralists misinterpret how the pie is distributed. Elitists believe that the upper class elite pull the strings of the government. They believe that wealth is the basis of power. This is not unfounded, however. Over a third of the nation's wealth is held by just 1 percent of the population. In fact, the median net worth of a United States Senator is over 1 million dollars (source). One cannot deny the influence of wealth and education in government power today.
A third theory, hyperpluralism, offers a different critique of pluralism. In this view, groups are so strong that government is weakened, as the groups' power cripples government's ability to make policy. Whereas pluralism says groups are a good thing for the political decision-making process, hyperpluralism says that there are too many ways for groups to control policy.