Marshall McLuhan was influenced by Harold Innis .

 Harold Innis talked about monopolies of knowledge , and that the holders of these tend to be conservative. As Marx talked about seizing the means of production, I'm not sure about his views of knowledge.

It follows from centres of knowledge, naturally, the theories of centres and margins. And this brigns some clarity, and perspective on  McLuhan's chapter on roads and paper routes and centre-margin dynamics  chapter.