Anti/Trump bias aside, I think they by and large lean left to a degree, some a little, some a lot.
The issue with this perception is largely due to where the MSM is located. The MSM is out of touch with middle America. By that, I mean the emphasis placed on many ideas in large cultural centers are lost in the heartland because those aren't the issues they can relate to. Instead of educating and informing, the MSM took the approach of shaming and ostracizing the less cultured. They chose to not make it relatable or even make an attempt.
Take the medias approach towards firearms as an example. By and large, most of us grow up owning, using, purchasing, and hunting with them. We are raised to respect and understand their lethality as most of us have killed something by puberty. Then the MSM comes along and tries to tell us all the problems with them and shame us into submission when we don't have a problem. The inner cities do.
You can extrapolate that example across a variety of issues, causes, and sacred cows of large cultural centers. The telling thing for me was the self reflection articles following the election by the MSM with many acknowledging they didn't even try to understand let alone visit the heartland. If the MSM wants credibility back, it's easy, go out and connect, not just study and ostracize us like some tribe of backwards Neanderthals.