The conscious and intelligent manipulation of the organized habits and opinions of the masses is an important element in democratic society. Those who manipulate this unseen mechanism constitute invisible government which is the true ruling power of our country.The author of that sentiment was Edouard Bernays, Sigmund Freud's favorite nephew. The old man always stayed with Bernays when the former was in the USofA; it was Bernays' appropriations of the old man's ideas which formed the basis of the 'industry' of which Bernays is considered the "father": advertizing/public relations (there's no difference between them, except in the rhetoric of those who hope to elide the synonymy of their practices and and ends).
Bernays was saying, in effect, that the appearance of 'liberty' and/or 'freedom' in a 'democracy' is the product of the manipulation of the 'unseen mechanism' by the those in the 'invisible government' who are privy to the machinery. It is this which maintains power in the hands of the elites, all the while conveying the impression--abetted by the feverish, expensive, pervasive propagandistic labors of the advertizing/public-relations industry--that, as the myths proclaim, the People are in control of their own political destiny, when in fact nothing could be further from the truth.