Political parties, as Strøm (2000, p. 180) maintains, are generally ‘the most important organisations in modern politics’. Along with co-operative federalism and parapublic institutions they constitute one of the three crucial ‘nodes’ of the ‘semisovereign model of governance’ Katzenstein (1987) developed to analyse patterns of policy-making in the Federal Republic of Germany. Not only do parties in this model serve as links between citizens and elected officials at the regime level (cf. Poguntke2002; more generally Müller 2000), they also connect the various tiers, arenas and corporate actors in the Federal Republic's decentralised state contributing to a peculiar mix of competitive and co-operative elements (cf. Holtmann 2000; Leonardy 2001; Renzsch 2000). As for political parties, this model is generally characterised by ‘the conjoining of the party-run state with statist parties’ (Katzenstein 1987, p. 377) and, more specifically, by a number of structural attributes that he believes to have profoundly influenced the formulation of centrist policies, which tend to be adjusted incrementally and largely irrespective of the party-political composition of the federal government of the day (Katzenstein 1987, p. 39).

This chapter seeks to map and analyse continuities and change of relevant structural attributes of the German party system at all three levels conventionally emphasised in the literature: (1) party in public office, (2) party as organisation and (3) party in the electorate, following the triad famously suggested by Key (1964).