One of the lessons of the rise of the Third Reich is that the right set of conditions can turn a democracy upside down virtually overnight. We say now that Trump won’t be able to do too much damage because support for him is abysmal and the public will raise a fuss. But imagine another 9/11, another national tragedy that gives Trump the sort of boost that Bush got (80%+) in the national polls. How much damage could he do with that before the public wised up?