Now I remember where I heard of him before, in Hawley's Right-wing Critics of American Conservatism. He's mentioned throughout the book actually but gets a section in a chapter on what the author calls localism. The Quest for Community is summarized. In it Nisbet defines community as encompassing all forms of relationship characterized by personal intimacy, emotional depth, moral commitment. social cohesion, and continuity in time. In that book and a later Twilight of Authority, Hawley says the key idea is that the central state grows as intermediate institutions decline.
Nisbet did not see democracy as preventing totalitarianism. He aimed at disentangling the unitary view of democracy from the pluralistic. The unitary view, similar to Rousseau's General Will, called for an end of previous social loyalties to regional and local authorities and the "construction of a scene in which the individual would be the sole unit, and the State the sole associate, of society." On that view all intermediate institutions fractuare society and hinder social harmony. A state built on this philosophy may have the formal attributes of democracy such as equality, but it creates "conditions of social dislocation and moral alienation." Such a democracy is no guarantor of freedom.
The pluralistic view of democracy maintains the importance of institutions and sources of authority that stand between the individual and the unitary state. Small-scale institutions that grow from the family, common interest and social needs protection against the totalitarian impulse. "Only in their social interdependencies are men given to resist tyranny that always threatens to arise out of any political government, democratic or otherwise. Where the individual stands alone in the face of the State he is helpless."
(The quotes are Nisbet's.)