Here is what some have to say:
Many jobs from northern states like Michigan, and Ohio, went to southern “Right to Work” states. Some manufacturers eventually realized that relocating in foreign countries would produce even greater profits. http://www.bloomberg.com/news/articles/2014-09-04/u-dot-s-dot-south-draws-global-manufacturers-with-low-taxes-cheap-labor
This migration caused anguish and resentment among blue collar workers who felt they had been sold out by both parties, to look for Trump to make things right. They could not care less about his lack of class or demigod-like mannerisms.
Hey, this is the USA. Things like this happen here.
Terrorists like the Charleston church shooter will often use the Internet to share their hatred. Some seemed compelled to do it.