If you'd told Ford Nation in 2010 that the guy they were about to vote in consorted with criminals, supported gun running gangs, spent less than 20 hours at work per week, abused his powers of office, use his city-paid staff for numerous personal reasons, would give his brother's drug dealer partner a 130k/year job, pissed away nearly $100m in cancelled contracts and smoked crack cocaine, they'd never have voted for him (even if as I believe, many voted because he justified their ignorant values).
We're where we are because with every new scandal, it's only slightly worse than the previous one. If cognitive dissonance grows gradually enough and with enough personal investment, you can get people to support the most outrageous things, and at each step they become more and more a believer.
The socio-psychological aspect of cognitive dissonance (and it's reduction) is incredibly fascinating, and incredibly disheartening.