If money in media were having an immediate and crippling effect on democracy then it would have already.
The history of American media is a history of very rich people growing, owning and acquiring media. They've always had this influence.
And yes it may be sub-optimal, but it is not new and therefore difficult to directly attribute recent changes to. In fact, it's somewhat arguable that the current predicament we find ourselves in is the result of making media less expensive to disseminate, not the opposite.
Our society and biology are poorly trained to reject incorrect information. So when small unethical actors begin to proliferate doing quick profit cycles on sympathetic populations, we see a lot of uptake for those ideas.
Want a great example that won't pick a big 2016 political fight? PETA. Despite being a rather ineffective activist group with a large incoherent message, they can inexpensively produce tons of populist media that helps keep them in people's minds and associate them (however wrongly) with helping animals.