CNN (and many other media companies) support Hillary because they are pro-corporate and pro-status-quo.
They have de facto supported nonsensical positions because CNN pioneered the "two sides to every argument" stupidity in their effort to look "unbiased". CNN's reporting is heavily distorted, but the distortion is usually giving credibility when it isn't deserved. Fox simply pushes their agenda directly, while CNN gives cranks a stage no matter how stupid their position is, because calling out even the obviously wrong is "biased". Often this involves conservative opinions (for varying definitions of "conservative"), but almost every opinion of every topic gets the same treatment from CNN.
I think in the US newspapers are more constrained in their biases, but as you say TV stations do take editorial views. But, as an example of regulation, only US citizens can own TV station in the US. Additionally, no single US TV station has anything like the viewer share that Facebook has.