This article gets it exactly right about why (normal) people are supporting Trump. He gets too harsh and triggers Godwin's Law at the end, but the core of the analysis is correct:
http://www.thedailybeast.com/articles/2016/01/04/how-the-p-c-police-propelled-donald-trump.html
Anyone who is baffled by Trump's popularity should read this.
I would add one thing though. The Republican Establishment deserves some blame for this as well, because they refuse to fight any of the crony capitalist, socialist, lawless, economically unsustainable, big government policies they claim to be against, so many old-school Republicans simply don't trust their leaders anymore.
PC oppression + Republican surrender = Trump