Why Does Rupert Murdoch and The Rest of Fox Employee's deny that Fox is a Right wing Media Outlet?

Atleast MSNBC Had the decency to suspend Olbermann and a few others for making campaign donations. Fox News repeatedly denies that it's a right wing outlet, that's what pisses a lot of people off. You see Bill O'reilly arguing with Jon Stewart that Fox News is not a right wing station. That's if people like Bill O'Reilly will lie about fox not being right wing, as fluent as he would drink a glass of water, what else would he lie about, a long with the rest of their host. Why Can't they just come out and say they support Republicans? I mean 50% Of the Presidency hopefuls are employed by fox. Fox News supports Tea parties, Supports tea party candidates. Spend day after day verbally assaulting everything the president says, does, if he so much as breathes to the East, Fox News will accuse him of Neglecting the West. So, why can't they just come out and say what they are? Why do they need to deny it?