Locke and Demosthenes

Consider Ender's game.
In this story two super geniuses take on the identities Locke and Demosthenes in order to have an imaginary debate. They are able to influence people with their arguments and thus control global policy. They do this by having greater knowledge of the subject and releasing those arguments they know will influence people towards the conclusion that they want. In the end they take over the world via this sort of deliberative persuasion.

Of course there are no Locke's to quite the extent of enders game in the world right now*, but given almost any field there are people who are much smarter and more knowledgeable than those they debate with and who could use that knowledge to give others a false impression of the state of the debate in order to drive them towards the conclusion that they want.