From Alexis de Tocqueville's Democracy in America (1840):
When men are no longer united among themselves by firm and lasting ties, it is impossible to obtain the co-operation of any great number of them unless you can persuade every man whose help you require that his private interest obliges him voluntarily to unite his exertions to the exertions of all the others. This can be habitually and conveniently effected only by means of a newspaper; nothing but a newspaper can drop the same thought into a thousand minds at the same moment. A newspaper is an adviser that does not require to be sought, but that comes of its own accord and talks to you briefly every day of the common weal, without distracting you from your private affairs.
Newspapers therefore become more necessary in proportion as men become more equal and individualism more to be feared. To suppose that they only serve to protect freedom would be to diminish their importance: they maintain civilization. I shall not deny that in democratic countries newspapers frequently lead the citizens to launch together into very ill-digested schemes; but if there were no newspapers there would be no common activity. The evil which they produce is therefore much less than that which they cure.
The more equal the conditions of men become and the less strong men individually are, the more easily they give way to the current of the multitude and the more difficult it is for them to adhere by themselves to an opinion which the multitude discard. A newspaper represents an association; it may be said to address each of its readers in the name of all the others and to exert its influence over them in proportion to their individual weakness. The power of the newspaper press must therefore increase as the social conditions of men become more equal.
I think that de Toqueville's assessment is fundamentally sound. Democracy requires social cohesion; social cohesion requires a shared national perspective among the citizenry.
Today there is no mass medium that speaks for the common weal. In most cities the major newspapers are nearly bankrupt and reduced to the level of USA Today in mainly reporting on sports, weather, and celebrity scandals. The handful of news magazines worth reading (U.S. News and World Report, for one) reach few households. Television news programming, to the extent that it can even be said to cover news in the form of fragmented segments, is partisan and untrustworthy. Worse yet is the lowbrow entertainment of talk radio.
As the old foundations of social cohesion -- religion, Western culture, and objective news reporting -- lose their influence, we should expect increasing divisiveness and volatility in politics and increasing disregard for civility in everyday life.