Political parties traditionally played an important role in the process of interest mediation, providing a structural linkage between civil society and the state. Various processes, however, have undermined that role. The membership base of political parties has systematically eroded, while it has been argued that a market logic dominates the electoral process. Various forms of professionalization have weakened the ‘party as movement’, while they have strengthened the ‘party in office’. All these processes mean that political parties are less able to perform their representative function than they used to do in the past. Parties, however, will not become obsolete as there is no functional equivalent for the functions they fulfill in a parliamentary democracy. Nevertheless, it can be argued that it is important that various other organizations and mechanisms are available to supplement their representative function within democratic political systems.