If by "unbiased" you mean "unethical," then yes, I agree.
Easy pickings of the left-wing's boogeyman. Left runs the media here, so there you go. For example you never see Keith Olberman (MSNBC) parodies. He is pretty loony himself, but he speaks truth to power to the left so he is left unscathed.
http://www.break.com/usercontent/2008/11/SNL-Skewers-Keith-Olbermann-598554.html