The media bias most people talk about is the bias they see in stories and headlines. But the bias you can’t see is just as insidious. I’m talking about the stories the mainstream media choose to ignore.

Journalists like to explain this as “news judgment,” a catch-all excuse that can explain away the most egregious bias. Strangely, though, the stories that don’t get printed or aired seem always to be the ones about things that could score points for conservatives.

There are two such phenomena occurring right now that have gotten almost no coverage in the national media: the tea party movement and Mark Levin’s new book. Do a Google search and see for yourself. Local papers are covering their local tea parties, but the national media have said hardly a word.

As for Levin’s book, Liberty and Tyranny: A Conservative Manifesto, it was No. 1 on Amazon the moment it was released. It’s No. 1 on Barnes & Noble’s Web site, and it’s at the top of Borders’ bestsellers. A book signing in Virginia last week saw lines rivaling an appearance by Miley Cyrus, but the only coverage you’ve seen about the book is on blogs and YouTube.

No network morning show has had Levin on to discuss the book. No major national newspaper has reviewed it. I’m sure this would be blamed on “news judgment,” but it looks like an intentional blackout to me.

The tea party movement got its start back in October when a blogger got the idea of sending tea bags to members of congress to protest the bailout mania sweeping lawmakers. Then, in February, when CNBC reporter Rick Santelli called for a Chicago “tea party” to protest Obama’s economic policies, things really escalated. Very quickly, people were sending tea bags to their congressmen and organizing tea party protests all over the country.

The tea party movement is interesting because it’s a protest by people who don’t normally protest things. They’re housewives and working people who usually are too busy to hit the streets with signs. Their lives are just too busy to engage in the kind of street theater so common to rent-a-mob lefty protesters.

But there have been no think pieces, thumb-suckers or DBI (dull but important) stories in the media to point out the different character of this movement, and its growing momentum. One need only to look at a Google map of planned tea party events to see the national dimensions of this phenomenon.

The media like to think of themselves as adept at spotting trends, and being the first to report them. The truth is, of course, that the media are always behind the curve, not ahead of it, since they never see a trend until it’s already full-blown. So, even when they decide to report on a trend or a movement, they’re already late to the game.

But it’s one thing to be late to the game and another not even to be in it, which is the case with the Levin book and the tea parties. An astute, objective editor or reporter would look at both of these and feel that something is brewing that warrants a story.

Astuteness and objectivity, however, are hard to find in journalism these days.

Jon Ham is vice president of the John Locke Foundation and publisher of Carolina Journal.