A mass formation is any organization that does not require its membership to submit to ideological authority or an ideological program. In Stalin’s example these include the soviet councils, the trade unions, etc.

For the purpose of our current moment, mass organizations are those groups that are formed or joined by Communists for a specific purpose or to mobilize and agitate among other workers on progressive issues; For instance, PSL’s ANSWER Coalition or it’s rent caravans — CPUSA’s organizing to get unions certified, etc. These are examples of mass organizations.

The purpose of mass organizations and vanguard organizations could not be more different. The purpose of the vanguard organizations right now should be to link up and consolidate all forms of struggle into one movement, one great army of struggle, against the capitalist state. The purpose of the mass organizations is to act as the “belts” and “levers” of the proletariat and to convey direction to the vanguard organizations — and for the vanguard organizations to interpenetrate and unify with the masses, to drive the masses onward from height to height, to intensify the struggle, and to draw ever-wider sections of the population into the fight.