Hardly inconsequential IMO. They influence public opinion. I didn't pay any attention to the "liberal bias" allegations till fairly recently (last couple years). It's absolutely there. I see it in headlines on CNN all the time. Most of the time it's subtle, sometimes it's just blatant. That's partly why I like to look at liberal and conservative sites for news, commentary, etc.
I just don't see liberal bias. I'm not even sure what that means. For economics I would assume that means we would see union reps on TV giving the side of the story of labor...same goes for newspapers. Labor would have its own section in the daily paper.
I just don't see that, do you?
How about in terms of political punditry? When's the last time you saw Noam Chomsky on any national political venue? How about Gore Vidal?
I watched the FOX news show this morning. Here's their pundit panel: a neo-con, a right winger, a moderate conservative, and a moderate. That's not exactly even-handed. And that is the norm for all major news stations.
I would say that when actual news reporting is done in the media, it is biased to business interests which almost always lean to the right.