The erosion of trust doesn’t result from more liars and plagiarists working in the business or a widespread decline in standards. In fact, it used to be that editors–like doctors–buried their mistakes. “Correction boxes” were rare. Now the competition (not to mention the Weblogs) hammers the media elite regularly, imposing more accountability.

So why are big news organizations about as credible as HMOs? First, almost all large institutions in America eventually turn into useful bogeymen; the more powerful they become, the more resented. Second, the line between news and entertainment has blurred; news often acts as a marketing tool for Hollywood, which in turn offers “reality” TV or fictional plot lines “ripped from today’s headlines.” If “the media” don’t distinguish clearly between truth and fiction, why should the audience? And third, cable TV has changed the public perception of the news business, ripping back the curtain like Toto in “The Wizard of Oz” to reveal news as it is being gathered but before it has been verified. To mix metaphors, when you see the sausage being made, full of gristle and fat and a lot of ingredients of mysterious origin, it looks awful.

But there’s one more reason: the Internet. I hate to admit it, but Matt Drudge put it well a few weeks ago when he said: “The statue of Peter Jennings has been pulled down.” The whole authority structure of mass media is being undermined by the ability of news consumers to move from passive to active, from accepting everything they read in the Times to searching and finding www.I-know-I-read-it-somewhere-on-the-Internet-so-it-must-be-true.com.

This fragmenting of media can be good. It gives the consumer more choices and perspectives. But there’s a danger of moving from spoon-fed to forked tongue. Readers now often look for news that simply reinforces their own world view and politics. They often assume that the truer version is what has not appeared in the Times or other mainstream outlets. That’s a lie as big as any Blair ever told.

The United States is now in danger of drifting toward a more European or 19th-century American “partisan” press. This kind of journalism can be more satisfying and exciting, but it’s less reliable and authoritative. Liberals may worry that the public now trusts George W. Bush more than The New York Times. But conservatives who are delighted to use Blair as a weapon against the “liberal” Times might not be so happy if a Democratic president is elected and the Times has less clout in standing up to him, as the paper did to Bill Clinton. When The New York Times loses power, the U.S. government gains it.

That doesn’t excuse this fiasco, any more than the good work of many Roman Catholic churches excuses the scandal of the pedophile priests. But as we flay the Times, let’s not forget how much we still need it. The only thing worse than believing everything you read in the papers is believing none of it.