An important question. The important question.
As I remember it, the answer was: in the first valid election which Hamilton studied, the majority of Hitler's supporters were in the more Catholic south of Germany. But by the time of the second valid election of the Weimar Republic, it was mostly people outside the big cities, in the north of Germany.
Here I add details from my own readings in museums and outside sources:
Strange as it seems, Hitler used entirely legal means (within the German constitution) to gain complete autocratic power.
Ok, he locked up all the communist politicians before the last vote of the German Parliament, but Parliament's last act was -- with, apparently, the help of Hitler's trading greater recognition of the Catholic church in Germany for their niggling vote giving him a parliamentary majority -- a vote to give Hitler total control and effectively disband the Parliament. Then, it seems, the question was put to the German people and 90% of them agreed with the new order.