Ok, let me start off by saying I will be the first to admit that Foxnews has a Right-wing bias on it programs. However, if you actually watch Foxnews, you will see a specific set of commercials. Fox will actually air commercials on their network calling for health care reform and stuff like that.
But, go watch all the other news channels (seeing how the rest are all liberal biased) and you will only see commercials supporting the left wing plans. ABC and NBC have refused multiple times to air commercials opposing the President's plan to reform healthcare. Who has more of a bias?
Oh yeah, I got another thing to tell you about Fox. Once again, I'm not going to say they're not Right-wing biased, but watch Hannity's Great American Panel. He almost always has a Democratic strategist on his show. It's not just his show either. O'Reilly has them on there on most of his shows.