In June 2003 a Washington Post-ABC News poll found that about 1 in 4 Americans (incorrectly) believed Iraq had used weapons of mass destruction during the recent war with the United States.  A separate poll in the same month found that 34% of Americans believed the United States had already found weapons of mass destruction in Iraq.  In September another poll found that 69% of Americans believed Saddam Hussein was personally involved in 9-11.  Even the Bush administration has been forced to admit that these claims are not true. These misconceptions are the outcome of a system of thought control called ideological hegemony. Hegemony operates through many mechanisms including the media, education system, newspeak and others with the primary function of maintaining support for the dominant socio-economic system in the United States.
In all class societies, the ruling class can maintain control through violence and/or ideology. If the majority can be persuaded that the rule of the ruling class is legitimate then it can be maintained with less violence. Examples of ideologies that serve this function include the divine right of kings, social Darwinism and Marxism-Leninism. All of them acted to legitimize the rule of specific elites in certain societies and helped those elites maintain power. Some hierarchical societies rely more on violence, others rely more on ideology. The United States relies more on ideology, although a certain degree of force is used.
In Russia prior to 1905 there were a number of large peasant revolts over the centuries that could have potentially threatened the power of the monarchy. However, all such revolts did not see the monarchy as the problem. They assumed that it was various “bad apples” which caused their problems, not the social system. The rebels believed the oppressive actions the monarchy took were the result of bad advisers, corrupt officials or other glitches in the system - but never the outcome of having a monarchy. This belief that the monarchy was not to blame, the system just needed a few reforms, helped prevent the system from being overthrown as most rebellions against the monarchy didn’t seek to overthrow it. The monarchy did not fall until after most stopped believing that the problems were the result of “bad apples” rather than being inherent in a monarchical system.
Ideological hegemony in the United States operates in a similar manner. Certain fundamental principles are never questioned - capitalism, private property, the state, imperialism and other assumptions. So long as those fundamental principles are not questioned debates can rage back & forth and all sorts of different positions can be formulated. The more vigorous the debate is the more it will tend to shore up the status quo as it will make society seem more open and pluralistic than it really is. Thought is bounded, with liberalism on one end, conservativism on the other end and various other ideologies in-between (I count libertarian capitalism as being within this spectrum). The legitimacy of private property, the state, etc. is always assumed.
For example, it is generally assumed that most US interventions into other countries in recent history are intended to be benevolent. Some may argue that such interventions don’t have the positive effects their supporters desire or that they aren’t worth the costs, but the assumption that the US acts with benevolent intentions, even if it makes mistakes sometimes, is assumed to be true. Similar assumptions are made about capitalism, the state, etc. Some may argue these things need to be reformed but the vast majority assumes they are legitimate. So long as that assumption is held by a large majority of Americans the system will be secure, just as the monarchy was secure in Russia when the vast majority assumed its legitimacy. Anyone dissatisfied with the status quo will end up being drawn to various reform schemes, voting for different politicians and the like instead of supporting the overthrow of the system.
These assumptions are both shared by the vast majority of Americans and transmitted to the populace through a variety of mechanisms. In an important sense hegemony, once established, is self-perpetuating. Those who believe in these ideas, to varying degrees, tend to advocate and promote them, passing them on to others and to the next generation. These values are also transmitted, often indirectly, in movies, novels, scholarship, entertainment and other forms of communication that reaches large numbers of people. This isn’t necessarily intentional or explicit.
Critics play an important role in perpetuating ideological hegemony. If even the most ardent critics of the current regime share these basic assumptions then it will serve to reinforce those assumptions. If even they share these assumptions then even fewer will question them, as doing so would seem insane. Those dissatisfied with the status quo will tend to become involved with movements and ideologies that accept these fundamental principles and therefore will not represent much of a threat to the dominant socio-economic system.
The kind of ideological hegemony that operates in America is different from the mechanisms used by totalitarian states to maintain control. Totalitarian societies tend to rely more on violence to control the population, although they usually also have an ideology to support the status quo. The United States does occasionally use violence to control dissent, such as the frame up of Sherman Austin, and has around 100 political prisoners.  However, force is not used against dissidents on nearly the scale it is in totalitarian states, where dissidents are systemically rounded up. Most dissidents in the United States can criticize the government with low odds of going to jail for it. So long as their ideas are kept marginalized, so long as the vast majority continues to believe in the system, dissidents do not represent much of a threat to the status quo. Allowing most dissidents to exist, but marginalizing their views, actually strengthens hegemony because it makes the system seem freer and more open. In a totalitarian system the spectrum is narrower and all dissent is suppressed, while the ideological hegemony that exists in the United States just marginalizes dissent, instead of suppressing it, and acts to insure that most people continue to believe in the system.
Neither ideological hegemony nor the existence of an elite ruling over the United States is some giant conspiracy. They are both the outcome of the way American society is set up and a long historical evolution. Hegemony is the result of the way the media, education system and other institutions are set up and have evolved. The structure of the system is such that those who are outside the liberal-conservative spectrum tend to be weeded out when rising up the hierarchy for positions involved in perpetuating hierarchy (editors, teachers, etc.), not as the result of a conspiracy but as the result of the way the system operates, and those who are not weeded out are marginalized. Whenever any society is divided into hierarchies (rich and poor, powerful and powerless) an elite is formed consisting of those on the top of the hierarchy. Several centralized, hierarchical institutions including large corporations, a powerful military and a bureaucratic state run the United States. Those on the top of these institutions, what sociologist C. Wright Mills called the power elite, have far greater power, wealth and prestige than those below them.
Hegemony operates through many institutions and mechanisms. The news media reinforces it by emphasizing facts that are consistent with the liberal-conservative spectrum while downplaying facts that might cast down on it. The education system reinforces hegemony by training the population to obey authority and indoctrinating children with the fundamental principles underlying hegemony, principles which they usually continue to believe as adults. Both of these largely exclude dissident views. Hegemony is written into the very structure of our language, through a process called newspeak. And there are also other elements to hegemony, but these are the main ones addressed here. In addition, some of these institutions have functions other than directly reinforcing hegemony. The education system is a kind of Keynesianism and the media helps create artificial scarcity, for example. These other functions are not examined here, the focus is on how each of these institutions acts to create and reinforce ideological hegemony.