The expression 'double party' must of course be used carefully. If it does not describe exactly the unique structure of the movements to some extent it makes evident something of the essence of this completely new-style creation in the history of political parties. At all events it puts an end to the popular idea that the NSDAP had been in fact the monolithic block that it seemed in retrospect. In addition it should be pointed out that a clear conceptual distinction and demarcation between the SA and the Political Organization (PO) is hardly possible, since their functions were by no means rigorously separated. The distinction is most easily apprehended, at least in the early stages of the movement, from the divergent organizational structure - the SA following more a military, the PO a regular political party model — as well as from the psychological and sociological characteristics of their members. See further, Wolfgang Sauer in Bracher, Sauer and Schulz, Die nationalsozialistische Machtergreifung.