Oh, definitely. But they might not be trolling on purpose; there is the off chance that they actually believe the stuff they're saying.
The irony is that Fox News was scored by UCLA study as being left of center: http://newsroom.ucla.edu/portal/ucla/Media-Bias-Is-Real-Find...
disclosure: I don't watch Fox, I read the WSJ and the NYT though I find CNN particularly infuriating and I'm quite far from being a Republican.
That said, they may believe that the ends justify the means.
When reading/viewing any type of media always keep in mind its origin, value, purpose, and limitation. I thank my school's IB Programme for that.