That world isn't imaginary: it exists in plenty of other democracies and they are doing fine. (Candidates in France for example are publicly funded and there are rules about how much can be spent to promote particular candidates).

that's a very incomplete view of Citizens United - the specific issue was not that it was published before an election - it was that paid for by a non-profit organization (Citizens United is a PAC). individuals are allowed to publish a movie, or view on their own w/o prohibition. Corporations and non-profits were not granted that right. Citizens United reversed that law, allowing corporations and non-profits (mostly PACs) to be able to express more political views. It's not crazy to think that organizations are not a person and therefore shouldn't be afforded rights that were intended for actual individual human beings.