First off all you are looking to take on what i call the universal law of balance when confronting Trump. That law being creation is always offset by destruction. In this cade of course Trump represents the destructive element within America.
A huge chunk of that 30% are folks that share Trump's internal violence streak whereby they too have a need to project violrnce upon others, especially weak minorities. They function, perhaps unwittingly so with some, as nature's negative offset to America's better angels. It's just the way nature and life roll.