Yes, that's it MrsT. The worse possible mindset comes from someone who is ignorant of their own ignorance.
With regard to Trump die-hards I think it will take much more than words for them to change their views. After all, unwelcome facts and opinions can always be dismissed as fake.
Only when Trump's policies directly impinge upon them and their sense of well-being/worth (healthcare, for example), will they begin to rethink his Presidency and even then, some of them will still blame Obama.