There was a pretty good documentry on the Aus equivalent of the BBC other night called 'The price of the American dream'. It looks at the huge increase in numbers of 'working poor' in the US since 2008. People are easily able to get jobs at the moment and the economy is growing rapidly, companies are making big profits, but the fast majority of those new jobs are low paid, part time with no benifits. People work 2-3 jobs doing 70-80 hours a week but still only make $1-2k per month and cant afford to save a deposit to rent a place, a lot of them are actually living in tent cities or short term accomodation shelters.
Watching these peoples lives you can see why they were desperate for a radical change and Clinton would not have provided it.
Trump was promising to be that radical shake up of the system. Even if these people didnt agree with everything Trump stood for it was enough to get a significant chunk of voters to vote for the radical change candidate over the status quo. A lot of them have very little to lose anyway.
http://www.abc.net.au/4corners/stories/2017/03/13/4633037.htm
Edit: I suspect it will be region blocked but you can watch the full thing here:
http://iview.abc.net.au/programs/four-corners/NC1704H006S00