Indeed. No, indeed, indeed. As a philosopher, I'm tempted just to say "indeed" and duck the difficult issue and leave that respectfully for you, but I don't know, and I think -- let me think. I suppose the idea I had in mind by "promoting" would be things like a press that took it on itself to explicitly outline the different parties' policies and to help readers work out which one they would go for, and I certainly don't think we need to see the press as doing that.
Distorting or perverting? I suppose lying about a central party policy might be one sort of case like that. Central political party policy. Misleading the public about a crime committed by a central politician might be another case. But these would have to be cases of sort of knowingly misleading. I'm not saying if you suspect this that you should be criticised for following up your suspicions but that sort of thing.