I took interest in the caricatures of "Kladderadatsch" and it stroke me that it seemed (even if quite politically biased, depending on the period) still quite satirical. But after one point, the drawings are basically a light hearted "Der Stürmer". Was there a clear cut, a direct take over from the nazi party or maybe just coincidence?
Please apologize for eventual mistakes: english is not my first language.
Both Kladderadatsch and its other Witzblatter contemporary, Simplicissimus, underwent a conservative, patriotic turn during the First World War, and while the latter managed to turn back to its centrist liberal mockery of both the left and right, Kladderadatsch's satire remained in this mode. The chief editor of the magazine from 1909 and throughout the Weimar period was Paul Warnke, a noted nationalist and positioned Kladderadatsch as the opponent of the Republic's left, especially the SPD. This rightward shift of the magazine led to a decline in its circulation and Kladderadatsch's ownership shifted during the Weimar period, thus making the magazine more of an organ of the right. The magazine first came under the ownership of the Hugo Stinnes' group, a German industrialist strongly associated with the conservative nationalist DNVP, and then H. and S. Hermann Verlag.
So Kladderadatsch was very well primed for the NSDAP's seizure of power and its editorial staff proved quite willing to adjust itself to Gleichschaltung of the Hitler state. In hindsight, the magazine's transition to something not that much different than Der Stürmer was really the culmination of long-term trends from the early Wilhelmine era. Already by the turn of the century, Kladderadatsch had long since abandoned its liberal heritage that had been one of its major characteristics at the magazine's founding in 1848. The magazine had already began to espouse nationalistic sentiments and was more closely affiliated with right-wing causes at the dawn of the twentieth century. The war and the contentious politics of the Weimar Republic accelerated this rightward shift, so that the magazine ended up in with only a narrow readership on the German right and its humor abandoned nuance to become just a shrill echo chamber for the Third Reich's propaganda ministry.
Sources
Allen, Ann Taylor. Satire and Society in Wilhelmine Germany: Kladderadatsch & Simplicissimus, 1890-1914. Lexington, KY: University Press of Kentucky, 1984.
Fulda, Bernhard. Press and Politics in the Weimar Republic. Oxford: Oxford University Press, 2009.