A lot of the voters come from the fact that most of the DNC abandoned them in the late 1980's and then used shame and blame for the fact that all the jobs were exported and large tracts of the country were left destitute.
Can you picture grocery shopping at a store in the middle of farm land to only have 10-15% of your milk product not be expired?
So for quite a few people the DNC = GOP, and the GOP was the only one that showed up to say "hi".
E.g. in multiple areas of Texas and Indiana there is literally no DNC candidates because they do not feel the areas matter.
So what do people cling too? Religious beliefs and tribal views because that is all they have left. Folks need to understand people lost hope back in the 1990s and the government has failed them consistently for nearly 30 years.
The American Dream for a very large tract of America has been dead for a very long time, so a cult of personality could easily sweep in and promise things and there was literally no options.
Obama won because he actually went and talked to those areas, but those that supported him got stabbed in the back in 2010 and 2012.
The views that the world sees and the reality for a lot of American is hugely disjointed.