Magic Man
Reaper of Conversation
I'm really not using your definition of "biased" in the manner you cite but more along the line of exhibiting favoritism.
That would be pretty much the same thing. Favoritism has the connotation of being unfair or unreasonable. The question is whether you think the show simply exhibits liberal viewpoints or whether it goes further by being unfair or prejudiced. If you think it's biased, then it would be the latter. If it's the former, it wouldn't be biased.