The trial of Dr. Kermit Gosnell, the abortionist charged with killing babies and neglecting women in his care, is now national news. There's no bigger story on the Web. Anderson Cooper covered it thoroughly Friday on CNN. The Washington Post's executive editor pledged to send a reporter to file dispatches from the Philadelphia courtroom. My contribution, "Why Dr. Kermit Gosnell's Trial Should Be a Front-Page Story," distilled the Philadelphia grand jury report and argued that those horrific, detailed allegations are thoroughly newsworthy by any reasonable standard. That premise is now conventional wisdom. The trial is likely to remain national news.

My article didn't speculate about why the story didn't play bigger in the national media prior to late last week. I didn't want that debate to overshadow Dr. Gosnell's actions or the failure to stop him.

But the debate about coverage is important and fascinating.

Journalists, news junkies, and casual news consumers are all offering theories of what drives the media. Wildly divergent theories. And every last one amounts to a fellow member of our polity saying, "This is my notion of how America's primary means of civic communication works."

There is, of course, no single explanation for why any news story unfolds one way instead of another. "The media" is an abstraction. It encompasses tv, radio, print, and digital; editors, reporters and bloggers; The Drudge Report, The New YorkerUSA Today and Feministing. Many of the factors that shape how a story is covered are seemingly random or just plain undiscoverable. But it's possible to refine our understanding of factors that did and didn't shape coverage.* With that in mind, let's scrutinize some of the wildly divergent theories of American media.

Keep in mind that my inclusion of a theory doesn't necessarily mean that I endorse it.