Can't dispute your observations, Tom. It doesn't take an actual conspiracy to produce a result that looks like a conspiracy.

Fox News. Talk radio. Washington Times. Wall Street Journal. Errrr.....wait. Another one will come to me...

I went surfing to research the origins of "liberal media bias" (more later), and found this list in Wikipedia:

Fox News, the Washington Times, New York Post, Wall Street Journal, and Chicago Sun-Times.

Media bias in the United States (Wikipedia)

(BTW, all the Wikipedia pages on this topic start with a gaudy warning that the page is disputed or controversial; nobody has an easy time with this one!)

The list dips into the regional level, which highlights the way that any analysis of political bias depends a lot on where you look. It's my strong impression that local media are more conservative overall than national media. It could be argued that conservative media is far more powerful than liberal media because it has more voices, and those voices tend to be closer to home, and thus more likely to be influential.

(Notice I'm not arguing that there's no bias in the news media. Of course there is. I usually read the Murky-News but pickup the Chron from time to time for chuckles, and, man, what a blast from the 60s past! The world has a psychedelic aura and "trailers" for hours after reading the Chronicle.)

I suppose you could stretch the "organized" thing far enough to take into account that most journalists tend to be run through the mill of liberal journalism schools. But that's probably less of a factor than the theory that liberals tend to be attracted to journalism by the glow of the "Woodward Factor." Report the news? We're here to change the world!

Pushing the explanation back to journalism school isn't enough, because now you have to ask why people choose J-school. And the answer might well be something like the Woodward factor.

But that got me to thinking about how the idea of assigning the media to political categories is a relatively new-fangled invention. Wikipedia credits Spiro Agnew with making one of the earliest claims of liberal bias in a November 1969 speech. (For you kids in the audience, Spiro "Spiggy" Agnew was Richard Nixon's VP, until his political career was tragically cut short by conviction and incarceration on charges of accepting bribes as Governor of Maryland. But I digress...)

The reason I was curious is that the archetype of the muck-raking/investigative journalist goes back long before Bob Woodward, by at least a century (or a lot more, depending on whether you credit the authors of English "broadsheets" with being journalists). "Muckraking" is technically the name of a school of journalism popular in the late 19th/early 20th centuries. There really is not a shred of evidence that Woodie and Bernie had politics in mind at the time; if they reflected on context at all, it's likely that they compared themselves to Upton Sinclair or Walter Winchell (does anybody remember their political affiliations?).

To be a muckraking journalist is to set out to change the world, but not (necessarily) for the political reasons you assume. It's more likely to be about change for its own sake--in other words, reform.

Although the term muckraking might appear to have negative connotations, muckrakers have most often sought to serve the public interest by uncovering crime, corruption, waste, fraud and abuse in both the public and private sectors.

Wikipedia

Since a liberal is broadly characterized as one who wants to change the world, and a conservative with an equally broad brush is somebody who resists change, I'd argue that coincidence is sufficient to explain the conservative perception of liberal bias: Liberals and reporters do indeed both want to change the world, but it's a logical fallacy to assume that their reasons are at all the same, let alone identical.

I think Occam's Razor would tell you that reporters are just being reporters, and that adding layers of political motivation needlessly complicates the explanation.