SpectatorWorld article by Roger Kimball.
In the context of Western societies, “the long march through the institutions” signified — in Marcuse’s words — “working against the established institutions while working in them.” It is primarily by this means — insinuation and infiltration rather than confrontation — that the radicals have triumphed.
The original article by Roger Kimball is The Two Souls of Marcuse’s One-Dimensional Man.