In heraldry, a compartment is a design placed under the shield, usually a landscape or wreath of some sort upon which the supporters are depicted as standing. It is a comparatively late feature of heraldry.
Usually when arms are augmented by supporters, a compartment will be added too.
... Socialists of America with the purpose of "realignment" - the aim of working within the Democratic Party and pulling it to the Left (pretty much the Trotskyist idea of ...