The current MSNBC shows - at least the two I watch reasonably often, Maddow and Olbermann - have little 'bias'.
'Bias is putting the desired message ahead of the truth - not telling the truth that supports a message.
If a Republican president ate a baby a day, some here would say that a reporter saying that - much less sympathetically interviewing the babies' families, much less saying anything critical about the practice - would have 'left bias', and the reporters who did not say anything about it, or provided 'spin' such as how some leaders in some tribal societies have practiced cannabilism, or how 'Democrat leaders killed many babies in their wars', or how much good the President is doing along with the baby eating, might be 'neutral', just 'telling the other side, fair and balanced'.
In these bias discussions, I've cited countless examples of where the actual 'bias' is; sites like Media Matters for America, headed by a former member of the right-wing propaganda machine who turned on it and decided to expose its bias after his experience accidentally as a gay man exposed finding out how it feels to be the target of their bias - what you don't see are practically any specifics on 'left wing bias'.
You do see a couple dishonest, trumped up false 'examples' - which say more about how little ammo the proponents have than they do about the existence of bias.
And you see a lot of repetition of the ideological claim of bias, using 'the big lie' technique of repeating the conclusion until it's unquestionably correct.
MSNBC today is not the counterpart to Fox. Fox is a propaganda machine, MSNBC isn't. They're not counterparts. One is misleading by design, the other generally is a counter to the deceit by pointing out the lies and telling a more accurate story. It's not all one sided, but it's a lot closer to that than to being two equally wrong sides.
MSNBC has its history of bias - as when after 9/11, they backed the Bush administration pure and simple, and having Phil Donahue on their top rated show, refused to let him say almost anything otherwise, first installing staff to limit what his show could say, then giving him a rule every anti-war guest required three pro-war guests, and finally cancelling his show while it had the top ratings on the network. That's bias by the real biased side. (Putting aside MSNBC's GOP former congressmans' show).
Let's talk about how 'freedom of speech' works here with a real example, as opposed to the pretty story about how 'the opposition' has a full voice.
LBJ chose to placate Republicans and start the Vietnam War. He didn't like the critics, who were helping the nation move to anti-war views.
The Smother Brothers included some bits that had jokes against the war. These weren't causing the network a problem; the show was unexpectedly a major hit, one of the top rated on television, and the public was largely sympathetic to the views in those jokes. Even Nixon months later ran on an 'end the war' platform.
But LBJ was personal friends with the head of the network, and he did not like the show's jokes, and the top-rated show was unexpectedly cancelled for only that reason.
We're not a totalitarian society where that happens to all 'opposition voices', but we're not the society where that doesn't happen, either.