UPDATE: Joe and Mika discuss this NB item. Video (0:57): Real (1.55 MB) or Windows (1.78 MB), plus MP3 (435 kB).

Joe Scarborough has pulled back the curtain on the liberal bias at MSNBC, describing an incident in which people in its newsroom ceaselessly booed President Bush during a State of the Union address.

The revelation came on "Morning Joe" today at 6:02 A.M. EDT. Joe was discussing a recent episode at the Seattle Times in which reporters and editors cheered the news that Karl Rove had resigned. Scarborough applauded Seattle Times Executive Editor Dave Boardman for issuing a memorandum reproving his colleagues. For more, read NB items by Brent Baker and Ken Shepherd.

Joe went on to describe a similar incident at MSNBC.

VIEW VIDEO OF JOE'S ACCOUNT OF THE NEWSROOM INCIDENT HERE. Note: that's newsreader Mika Brzezinksi heard murmuring in assent, though one has to wonder just how thrilled she was by Joe's candor in outing her fellow MSNBC liberals.

Seattle Times Executive Editor Dave Boardman, who in a Tuesday e-mail to his staff had scolded them for cheering Karl Rove's resignation (Ken Shepherd's NewsBusters item), wrote a follow-up e-mail on Wednesday in which he conceded the political display matched the “blue” perspective of the majority in his newsroom where, like most of journalism, reporters are driven by “activism.” Boardman acknowledged:

“If we wore our politics on our sleeves in here, I have no doubt that in this and in most other mainstream newsrooms in America, the majority of those sleeves would be of the same color: blue. Survey after survey over the years have demonstrated that most of the people who go into this business tend to vote Democratic, at least in national elections. That is not particularly surprising, given how people make career decisions and that social service and activism is a primary driver for many journalists.”