Tonight may be the last of the primaries, but the discussion of the cable news coverage will no doubt continue for months to come. MSNBC has bore the brunt of much of the criticism, from a candidate, a competitor, and many voices in between. Now, TVNewser speaks with a high level source inside MSNBC, who sheds light on some of the inside rumblings.

> Update: NBC News SVP and MSNBC exec in charge Phil Griffin responds...

MSNBC has drawn criticism from pundits from both parties, other journalists and the White House, for the perceived, and often obvious, leftward shift of their lead political anchors Chris Matthews and Keith Olbermann.

"Every Tuesday night Keith is up there as the face of NBC News. That's a problem," says our source. "[Tim] Russert is upset about it. Russert has spent 20 years building credibility. All of a sudden he's taking questions from Keith Olbermann, the Daily Kos blogger?"

The insider says Olbermann's election night partner has reservations as well: "Chris Matthews is quite pissed about it. He knows a lot about politics and he takes it seriously. He's so close to it that he's not that political. He's not an activist — Keith's an activist. That's the difference."

Asked for a response, an MSNBC spokesperson tells TVNewser, "Your source is ill-informed and the assertions are laughable."

With the primaries finished, the focus moves to the general election. "What's it going to be like in the general election now that everyone knows we're the in-house network of Barack Obama?" asked our insider.

"There's a huge difference between rooting for one side in a Democratic primary, and another one to take sides in a general election and go out and openly root for a candidate. You can't do that," said the insider. "You think Russert is going to put up with that? Election night coverage in November with Chris Matthews and Keith Olbermann?

"The key is his willingness to quit," says our source about Olbermann. "And he means it. He has convinced management of that. They are convinced that he will walk. He behaves like a man who has nothing left to lose. He is not central to MSNBC, he is the center of the MSNBC ratings strategy. We hang the entire schedule on him."

What about Olbermann blogging now at The Daily Kos? "That's insane," says the insider. "If he was writing long pieces for The Atlantic, or The New Republic, it's different. It's partisan, is what it is. It's also just low and stupid."

Still the insider sees the move to the left as a successful short term strategy. Countdown with Keith Olbermann has been the highest rated program in all of cable news in the A25-54 demo four times during the last two weeks.

"There's a very large untapped market of liberal TV viewers," says the insider. "It's probably smart in the short term. Fox has succeeded because there are a lot of alienated conservatives who thought no one was speaking for them. All of a sudden there are huge numbers of liberals who feel the same way."

> Update: NBC News SVP Phil Griffin tells TVNewser, "Whoever you're talking to knows nothing, it's that simple. MSNBC has offered the most interesting election coverage this season and the audience is responding. We're thrilled that Tim Russert chooses to be part of that coverage. If your source doesn't, they should leave."