MSNBC's concerted tilt to the left just got more top-heavy with the official addition of the Rev. Al Sharpton as the network's newest full-time host.

Sharpton, who has been auditioning for the past two months in MSNBC's 6 p.m. ET slot, will begin helming the new PoliticsNation at that hour this Monday (Aug. 29).

The heat-seeking firebrand joins a roster of like-minded politicos who already have their own shows. Sequentially from 7 to 11 p.m. ET, they are Chris Matthews, Lawrence O'Donnell, Rachel Maddow and Ed Schultz.

MSNBC president Phil Griffin, who made the announcement Tuesday, said that Sharpton has "always been one of our most thoughtful and entertaining guests. I'm thrilled that he's now reached a point in his career where he's able to devote himself to hosting a nightly show."

Sharpton pronounced himself "very happy and honored to join the MSNBC team as we collectively try to get America to 'Lean Forward.' It is a natural extension of my life work and growth."

In reality, "Lean Forward" means "Lean Left" in the same way that arch rival Fox News Channel's long-entrenched "Fair and Balanced" slogan really means "Fair to the Far Right." But MSNBC clearly has FNC outnumbered at this point in terms of weeknight hosts with unwavering political views.

In a recent chat with a small circle of writers during this month's Television Critics Association press tour, Griffin emphasized that "the media landscape's changed. You've got to stand for something. This idea that you're going to be distant and unemotional in a world where there are so many media outlets -- you can do it, but . . . " His voice then trailed off rather than finish the obvious point that has caused NBC News anchor Brian Williams and his predecessor, Tom Brokaw, to distance themselves from MSNBC, rather than be seen as part of an obvious and growing partisan crowd.

In an earlier press conference with TV writers, Griffin said that his network has now trained its sights on FNC after consistently beating the comparatively down-the-middle CNN in the prime-time Nielsen ratings. "For the first time," he said, "we are beginning to chip away at Fox News Channel."

But at what price to the public discourse in times when compromising and reaching a middle ground increasingly are dirty words in both Washington and in the all-our war between MSNBC and FNC? Republican presidential candidates are mostly buffoons on MSNBC and thoughtful alternatives to President Obama on FNC. There's basically next to no in-between, with Sharpton for one inviting a token Republican on his show every night for the sole purpose of ridiculing and/or talking over that person.

"I think it's easy to caricature us as the opposite of Fox, but I don't really think we live up to the caricature," said Maddow, who joined Griffin, Matthews and O'Donnell on the press tour's MSNBC panel. "I think that there is a lot more nuance and more unpredictability on our side . . . They [FNC] really are pushing a party line, not every one of their hosts, but in the vast majority of their coverage. I think we are more unpredictable."

Matthews said he even voted for George W. Bush in the 2000 presidential election because "I thought he'd have some common sense instead of be taken over by these bookish right-wingers that introduced him to this neo-con crap, and he got sold on it."

At an earlier press tour session, CNN flagbearer Anderson Cooper noted "it's not an easy thing that CNN is trying to do" -- namely report the news with at least a semblance of old-school objectivity. "When a big event happens, people turn to CNN because they know not only are they going to have people there covering it, but they're going to cover it in a way that's non-partisan, that's not left or right. When there's not a big news event, that's when the ratings dip and it becomes more difficult for CNN . . . When you're not trying to be partisan but when you're trying to be aggressive just about the facts and what is true, it's often not as entertaining as some of the others -- and they [CNN] have had some trouble with it."

Cooper will be launching his new syndicated daytime talk show Anderson on Sept. 12. (Check local listings.) On CNN, meanwhile, his presence will be expanded to twice nightly with an 8 p.m. ET first-run of Anderson Cooper 360 and a 10 p.m. ET repeat.

MSNBC's Griffin gives every indication that he won't be paying much attention to anything CNN does in prime-time, even though he predicts that someday "they'll be back" as a strong ratings contender. Meanwhile, the "progressive attitude" continues to bloom and grow at MSNBC, with Sharpton the latest to take offense at anything the political right says or does.

It's a network where Matthews can happily call Republican presidential candidate Mitt Romney "a mood ring" before adding, "I look at 'Chet,' whatever that guy's name is -- Rick Perry. He ought to be a Chet . . . I don't know what he is exactly, but I don't think he's authentic."

Perry and thrust/parry and thrust. What a country we're becoming.

Read more by Ed Bark at unclebarky.com