The same pattern repeated itself through the three networks’ coverage of the other events of the day. The formal newscasts for all three networks were fairly straightforward but the commentary that came before and after was anything but. MSNBC, in its commentary, tended to love whatever the Democrats had done that day. CNN has so many commentators it almost can’t help but be on all sides of every issue. Fox, meanwhile, was raising an army to overthrow the government.

Here are some more representative examples. They might seem chosen to make a point; they were not. They are admittedly impressionistic, but we think a fair sampling of what was on the air that day.

On the Senate compromise on health care reform:

MSNBC—Democratic Senator Ron Wyden of Oregon called it “a godsend.” Howard Dean said “the Senate bill really does advance the ball.”

CNN—Representative Barbara Lee, a California Democrat, called it “the type of coverage that they [her constituents] deserve.”

Fox—Neil Cavuto posed this question to independent Senator Joe Lieberman of Connecticut: “Senator, they just didn’t put lipstick on a pig? It’s still a pig, right?” Lieberman was noncommittal on the porcine nature of the compromise, but assured he would vote against it. Hayes of The Weekly Standard said, “it is absolutely insane.” Former Arkansas Governor Mike Huckabee said, “It is the lump of coal in our Christmas stocking.”

On climate change:

MSNBC—Jonathan Alter of Newsweek, addressing Sarah Palin’s claim that climate change is not necessarily the result of human activity: “Her bigger problem, if she wants to be a candidate, is that she’s on the wrong side of history. She’s on the wrong side of science. She’s on the wrong side of politics here.”

CNN—Kitty Pilgrim, CNN correspondent: “The United States is falling behind the rest of the world in what some see as the cleanest energy option available, nuclear power.”

Fox —Amy Kellogg, Fox correspondent: “. . . stolen e-mails suggest the manipulation of trends, deleting and destroying of data, and attempts to prevent the publication of opposing views on climate change . . . .”

We could go on, but the pattern would not change.

The three networks are, of course, all in the same television business, but even apart from expressions of ideology each approaches its business differently, each seeking its own distinct niche in the modern television ecology. One large difference is apparent in their staffing structures. Of the three, CNN produces and broadcasts much more news content and has many more reporters reporting from many more places. It has a total staff of about 4,000 people, according to the Pew Project for Excellence in Journalism’s latest available report. On December 10, for example, it was the only one of the three networks to feature on-the-ground reporting from both Pakistan and Virginia on the case of the five Americans arrested in Pakistan. CNN’s newsgathering superiority was even more striking in the aftermath of the January earthquake in Haiti.

With the exception of Larry King’s interview show in the evening, it runs news programming more or less all day long. CNN includes opinion and analysis as feature inserts on its news shows, an adjunct to its news operations, but its great strength is news. The commentary often feels forced and superfluous. Fox is the opposite. It includes the news operations as an adjunct to opinion and analysis. It is much more of a talk-show network than a news network. In fact, it mimics one of Ailes’s first ventures into television news programming, an NBC-owned all-talk channel called America’s Talking. Fox News uses this model much more than it does CNN’s news model.

The perceived problem is not that Fox’s straight news is relatively bias-free and its opinion programming overwhelmingly conservative. The problem is that the news portion is very small and the opinion portion very large. It would indeed be like a traditional newspaper opinion-news division if the ratios were reversed.

Fox has a reporting and editing staff about one-third the size of CNN’s. Fox has many fewer bureaus, both domestic and international (again, about one-third CNN’s total). From personal experience covering news around the world, you almost always run into a CNN crew or stringer. You almost never run into a Fox reporter, and never one from MSNBC.

Terry McDermott spent thirty years at eight newspapers, most recently at the Los Angeles Times, where he reported from more than twenty countries. He is the author of the upcoming The Hunt for KSM: Inside the Pursuit and Takedown of the Real 9/11 Mastermind, Khalid Sheikh Mohammed.