You are incorrect. The German people did vote for Hitler. In 1932 the Nazis were the most popular party in Germany. Paul von Hindenburg named Hitler Chancellor in 1933. Once Hitler was chancellor he used the Reichstagsbrand (probably a false flag by the Nazis) to gain dictatorial power in a matter of some months.

In 1932 there was no monarchy anymore.

The German people were suffering under the terms of the Treaty of Versailles and were desperate for change. Similar to Hitler (albeit orders of magnitude worse), IMO a LOT of people voted for Trump because they are desparate for change.

In Weimar Germany there were few good choices. The wealthy industrialists who had done well under the monarchy were not so jazzed about a republic and undermined it. They thought they could control Hitler. They were obviously wrong.