The legal regulation by constitutional and public law has trends to become the norm in European representative democracies. What are the implications in normative and "praxis" terms of this development? How does legal regulation influence politics and especially the instruments of politics such as political parties? The Federal Republic of Germany constitutes the first state to have embarked upon an extensive regulation by law of political parties, thus constituting itself as an example that was later to be followed by other states in Europe. In my paper I will explore, using the Federal Republic of Germany as an example, the influence that the legal regulation of political parties by law has had upon the nature of political parties, as instruments of politics, as well as over the very content of political parties as such. The influence upon the normative and formative aspects of politics that the legal regulation of political parties has will be explored as a result. Such an analysis is needed in order to understand the way that representative democracies have been evolving in the recent past and as they will in the near future. The legal regulation of political parties by constitutional and public law raises the question of the nature of political parties and the question of the relationship that exists between political parties and the state, as firstly established in the Federal Republic of Germany, which was to function as the leading paradigm for other representative democracies in Europe.