Why are most newspaper reporters and editors liberal? I've been working in the business for more than 20 years, and I can't give a quick, definitive answer to the question. But I do think a contributing factor is that editors, like other managers, tend to hire and reward staffers who think as they do. They see their positions as neutral, which is human nature -- and is reinforced by the fact that the folks in the desks around them vote the same way they do.

When they read about complaints of media bias, editors write the criticism off because they see reporters every day trying to cover stories fairly and succeeding. They fail to notice that their shared ideology limits what they see as stories.

Which is why, I believe, that Fox News Channel ratings are so high. As the New York Times reported, CNN reached 271,000 viewers aged 25 to 54 in prime time in April, less than half of Fox News' 668,000. In the first quarter of 2009, Fox News beat CNN and MSNBC combined in the Nielsen ratings.

Liberals mock the news network's "fair and balanced" slogan. But if you read your average newspaper, then tune into Fox News or listen to conservative talk radio, it evens out. People hungry for a conservative outlook in print aren't going to find it in the news or features pages. Liberal newspapers helped build conservative media.

I should note that there's a world of difference between Fox during the day and Fox after dark. Primetime programs feature conservative hosts trading on their opinions, while Fox daytime features straight reportage.

The network's full-tilt promotion of the TEA (Taxed Enough Already) party protests on April 15, alas, undercut the whole network's credibility as reporters covered events at which Fox News biggies like Sean Hannity and Glenn Beck were star speakers. Not fair. Not balanced.

CNN execs have responded to the success of Fox News by noting that their own audience numbers and profits are up. They also argue that their brand is purer because, as CNN president Jon Klein told the New York Times, "There are several networks that reside in the cable news category, but only one that reliably delivers the news unbiased."

Well, not quite. It turns out CNN has its own TEA Party baggage. Covering a protest in Chicago, veteran reporter Susan Roesgen lost her cool. She interviewed a man protesting high taxes and government debt with his 2-year-old and began to argue with him: "Do you realize that you're eligible for a $400 credit?" Roesgen asked him. And: "Did you know that the state of Lincoln gets $50 billion out of the stimulus (package pushed by President Obama)?" It was as if Roesgen thought she were White House Press Secretary Robert Gibbs.

Then she dismissed the event as "anti-government" and "anti-CNN" -- and the product of the "right-wing conservative network, Fox."

Asked about Roesgen, CNN's response: "No comment." In this space I have lamented what seems to be the advent of Designer News, that allow consumers to cull out undesirable viewpoints and information.

The irony here is that newspapers have written fawning stories about Google and Twitter and free classified ad sites as if they are all good. But when newspapers cover Fox News, they have this need to write the network off as right-wing -- end of story. Nothing to learn there, right?

Clearly there is an insatiable appetite for news from a conservative perspective that the folks who run newspapers continue to overlook -- except in the opinion pages.

There are days I wonder if newspaper and network news execs cannot change by broadening their ideological diversity -- even to save themselves. They'll keep telling themselves that they are unbiased -- up until the end.