Clearly, this shows a liberal bias on the part of all members of the MSM. Of course, that's a load of crap, but you know, those that consider her a darling of the base will buy whatever she throws out there.
However, the point isn't that she's trying to use one cherry-picked quote to paint a broad stroke over all the media, though that is important. Instead, one has to look a little bit deeper. I recall when in law school we were taught that you have to present all the law that you find, whether it is beneficial for your client or harmful - in other words, you have to tell the judge the whole story. This also means that you need context for what you present before the court. If you have text from a deposition wherein the defendant says "Yeah, I shot the guy," then it's disingenuous to not present the sentence immediately preceding it that says "I saw him with his girlfriend and they looked cute so I grabbed my camera."
The reason why this matters is that if you read the quote attributed to Cronkite above, and it is his quote, then you will note that he qualifies what he says with the words "by my definition." This begs the question, what is "his definition?" Well, in order to find that out, what one must do is actually look at the ENTIRE QUOTE:
Playboy: Implicit in the Administration's attempts to force the networks to "balance" the news is a conviction that most newscasters are biased against conservatism. Is there some truth in the view that television newsmen tend to be left of center?
Cronkite: Well, certainly liberal, and possibly left of center as well. I would have to accept that.
Playboy: What's the distinction between those two terms?
Cronkite: I think the distinction is both clear and important. I think being a liberal, in the true sense, is being nondoctrinaire, nondogmatic, non-committed to a cause - but examining each case on its merits. Being left of center is another thing; it's a political position. I think most newspapermen by definition have to be liberal; if they're not liberal, by my definition of it, then they can hardly be good newspapermen. If they're preordained dogmatists for a cause, then they can't be very good journalists; that is, if they carry it into their journalism.When you read the entire quote, you see what Cronkite meant, and that he was very clearly distinguishing between a political position and a state of mind. But that doesn't score pity points when you are making a career out of playing the victim.