So where's the line between "active manipulation" and merely "disseminating information"? Maybe we should just ban political ads entirely, on the principle that an uninformed electorate is better than a misinformed electorate. Or if we're going to distinguish between "informative" and "manipulative" advertising, who gets to be the judge of that?
Also, tf corporations don't have free speech rights, or can't spend above a certain amount of money on those rights, where does that leave The New York Times Co.? And if you think the NYT is "special" because it's part of the "press", then who gets to decide which companies are officially sanctioned "press" companies and which aren't? What about Comcast, would they get special corporate free-speech benefits by virtue of owning NBC?
The reality is that overturning Citizens United would mean that the government would have to get very involved in making a lot of subjective calls along these lines, which I would think would be very troubling for someone who "detest[s] all forms of censorship".