Marx and Lenin taught that power flows from control of the means of production and the State. Gramsci argued that in addition to control of the economy and the State, in modern Capitalist society control of the culture was essential to seize and hold power. Gramsci's insights on the critical importance of cultural revolution certainly seem to have been borne out by the history of the last 60 years. Mass politics today have, more than ever, become culture wars between the Left and the Right.
Good point.