Perhaps you could also mention the culture changes? From the nationalistic and militaristic society under Wilhelm II to the anti-war and pacifist groups that were around during Weimar era. The loss of WW1 and the Treaty of Versailles meant that some people had kind of lost faith in the militaristic Weltpolitik that Wilhelm promoted during his reign because they saw first hand the struggles of being in Germany through the food shortages and things like that.
I guess the aftermath of WW1 also meant that it wasn't the aristocrats in government office anymore. Ebert wasn't of incredibly high status and he became president, so perhaps you could also talk about the differing class structures, which allows more mobility for the upper classes because of the Weimar democracy?