Answer:
No. In Germany, as in many European countries, democracy failed in the interwar period. In Germany (unlike, say, Italy) the dictatorship that came to power was antisemitic, but that doesn't make democracy or failed democracy a cause of the Holocaust.
(In the late 1940s the view that 'democracy caused Nazism' was popular among some ultra-conservative hardliners in Germany, who equated democracy with 'mob rule').