I would imagine Joseph Goebbels would have been handed control of the country (I mean he actually did succeed Hitler, maybe for only a day, but had enough power within the Nazi Party to do it nonetheless) but he was Hitler's Closest Hand, as well as perhaps one of his most devout followers. He didn't have the Charisma that Hitler had, but he was a zealot through and through, and probably would have taken his duties as Fuhrer exceptionally seriously, and with vigor. He would've made a great (albeit terrifying) Leader.
Bookmarks