The argument that Hitler confiscated guns does not seem to be supported by history, at least according to a law review article from 2004.
The author walks through the effort to try to develop the idea that he did however. Its a good look at how history can be spun for political purposes. It would useful to investigate how much political ignorance is the result of a conscious decision to not become educated about something because ti doe not benefit us to do so, and how much because of exposure to disinformation.
Even though we may practice rational ignorance, we rarely fess up to it.
