MSNBC has taken off the mask and revealed itself as a lefty network. The NYT dutifully reports this and touts the channel’s ratings results.

Riding a ratings wave from “Countdown With Keith Olbermann,” a program that takes strong issue with the Bush administration, MSNBC is increasingly seeking to showcase its nighttime lineup as a welcome haven for viewers of a similar mind.

Lest there be any doubt that the cable channel believes there is ratings gold in shows that criticize the administration with the same vigor with which Fox News’s hosts often champion it, two NBC executives acknowledged yesterday that they were talking to Rosie O’Donnell about a prime-time show on MSNBC.

Oddly, for a story centered on TV ratings gold, there’s only one mention of any actual ratings. And even that’s vague at best.

The channel has done so much as Fox News did beginning in 1996, when the president was Bill Clinton, a Democrat. On some nights recently, Mr. Olbermann has even come tantalizingly close to surpassing the ratings of the host he describes as his nemesis, Bill O’Reilly on Fox News, at least among viewers ages 25 to 54, which is the demographic cable news advertisers prefer. Most of the time, though, Mr. O’Reilly outdraws Mr. Olbermann by about 1.5 million viewers over all at the same hour, according to Nielsen Media Research.

So that’s what the NYT says. What does the TV Newser scoreboard say?

Olbermann is a distant second in a four-way race in the prized demo. And check the total viewers number — O’Reilly still more than doubles Olbermann’s viewership number. Check out previous scoreboards and it’s tough to detect a ratings wave. The very occassional ripple, maybe, but a wave? Hardly. Olbermann is soaring to stay right where he’s been for eons.

Now, that’s not to say that MSNBC isn’t eating into Fox or that Fox isn’t losing its ratings dominance on the edges. That is happening, but that can just as easily be explained by Fox’s increasing focus on tabloid stories and sensationalism as on anything MSNBC is or isn’t doing.