This just in: MSNBC is a liberal opinion network

Pssst. Keep this one under your hat.

MSNBC is the most opinionated of the three cable news networks.

At the prime-time home of Al Sharpton, Chris Matthews, Rachel Maddow, Kirk O’Donnell and outgoing Ed Schultz/incoming Chris Hayes, “Opinion dominates reporting,” the Pew Research Center’s Project for Excellence in Journalism has learned.

The network devotes — are you sitting down for this? — 85% of its airtime to “commentary/opinion” and 15% to “factual reporting,” as measured by the media think tank’s “news coverage index” and reported in its “State of the News Media 2013.”

The corresponding opinion/news percentages for MSNBC’s cable competitors were: Fox News (55/45) and CNN (46/54).

“On cable, the news structure of the three channels — the mix of interviews, packaged segments and live coverage — has changed,” the report opines. “After relying on significantly distinct formats five years ago, the three rivals now look strikingly similar.”

Even if Pew’s own “news coverage index” did reveal striking differences in the coverage mixes between an opinion-dominated MSNBC and the more even balance between news and opinion found on its rivals.

But, whatever.

The report also found that the traditional differences between daytime and evening programming are blurring at all three channels, with the breaking news and expensive live event coverage long typical of daytime giving way to cheaper talking-head interviews.

If the revelation that MSNBC is dominated by liberal commentary is a shocker, just wait — rumor has it a next-generation “news coverage index” detects liberal bias in mainstream news reporting.