The answer to that is going to be multi-faceted. It can't be distilled down to one reason, there may be a majority held issue, but certainly not only one issue. I think it's clear there were a lot of people sick of the state of American politics. The lobbyists, .01% and their undue influence. Much of my family lives in the US and while when I cross the border I never notice much difference socially, the few differences there are, are quite stark and the politics are one of them.
- The politics are extremely partisan and the viability of the extreme right as a relevant political force is more real than any other first world nation I can think of. For context, the democrat party is more right than the our Conservative party here.
- The enshrinement of the ability to arm yourself.
- The religious right.
Those are pretty strong emotional hooks that I see Republicans pander to to garner votes. Trump played into all of those, but I don't think he actually gives a shit about any of the issues those things generally encapsulate, except perhaps being anti-immigration and anti Muslim.
I think the main driving force was the appeal to ripping up the back scratching, big money fueled .01% percent corrupt government that has been running rampant in the US. The irony is that a member of that very same .01% is who was elected to that end... so there is that. If that was the goal of the electorate I also think only Trump could have won to that end. I don't think America is ready to elect someone like Sanders and may never be. Even though the country has all sorts of huge socialist programs that drive it, the 'socialism' boogeyman has been demonized to the point Sanders would have never won. Just look at Obama's attempt to provide universal health care, it was a good attempt but he couldn't manage a real single payer universal health care system. Instead it's the pseudo hybrid mess he managed. You'd need to completely eliminate the corporate health insurance companies and move everyone on to single payer universal to manage what most European countries. Canada and some South American nations have. Sanders' notions of things like free university and the like would have had him decimated by his opponent.
I would be most concerned now with how many of the crazy things Trump pushed on his path to election were serious intentions. I'd be hoping it was mostly all bullshit and he was just pandering to the generic Republican audience to get their votes. How significant a portion of his support base is it that believes these things are really going to take place ?
- Building a physical wall on the border with Mexico and somehow getting them to pay the 10+ billion it will cost.
- Tracking Muslim members of the population.
- Killing the families of terrorists and torturing people.
- Destroying a nebulous terrorist organization that has no real 'home base'
- Instituting draconian trade tariffs with China, the country that produces near everything, and making the cost of everything go up significantly for Americans.
- Throwing Clinton in jail.
- Abolishing abortion and 'punishing' women who have one.
I don't remember everything, there is probably a lot more crazy I think it's safe to say none of that shit is going to happen. He might play around with some of it, but not of it will come to fruition. The one I'd be really worried about are any attempts he makes with anti-terrorism in so much as it amounting to expeditions into other countries.
With an electorate that split near 50/50 in who they wanted to win. How much of the 50% that supported him was enthralled by the crazy campaign points that won't come to pass and how will that effect their approval of him when he is expected to be the non politician. ie. Not lying (LOL), corrupt etc and keeping promises. He won't be able to do anything on that list unless his plan is to suspend citizen's rights and go full crazy, which while something to worry about, is not very likely.