The Federal Republic of Germany is a federal parliamentary republic, based on representative democracy. The Chancellor is the head of government, while the President of Germany is the head of state which holds a ceremonial role but substantial reserve powers. Executive power is vested in the Federal Cabinet (Bundesregierung), and federal legislative power is vested in the Bundestag (the parliament of Germany) and the Bundesrat (the representative body of the regional states). There is a multi-party system that, since 1949, has been dominated by the Christian Democratic Union (CDU) and the Social Democratic Party of Germany (SPD). The judiciary of Germany is independent of the executive and the legislature. The political system is laid out in the 1949 constitution, the Grundgesetz (Basic Law), which remained in effect with minor amendments after 1990's German reunification. The constitution emphasises the protection of individual liberty in an extensive catalogue of human rights and also divides powers both between the federal and state levels and between the legislative, executive, and judicial branches. In many ways, the 1949 Basic Law is a response to the perceived flaws of the 1919 Weimar Constitution, which did not prevent the rise of the Nazi party in 1933.