It was never really the reason that news broadcasts aimed for fairness. They aimed for fairness because they were journalists, and they considered it a point of pride to be accurate and informative.

The broadcast networks (including Fox affiliates) still aim for that, despite the end of the fairness doctrine. But their markets have been eaten into by cable networks, some of which were explicitly founded as propaganda machines and discovered that people preferred it as entertainment.

It probably does. If your editor, boss and all your colleagues support candidate X and you come up with a story that hurts candidate X, will you really get to publish it? Will you even try to come up with such a story? I'm not saying it's impossible to get this right, but under the current climate I don't think its possible.