The stock market is at an all time high, but I don't think most Americans are doing well economically, as globalization and tech has affected employment, and wages have stagnated for decades due to that, and the system being rigged against ordinary people. Here's a good post by Robert Reich on this: http://robertreich.org/post/107998491550
And that in large part explains how Trump got elected...although it's important to note that he did lose the popular vote by a historic margin, and barely won the electoral college.
I watched this breakdown of the elephant chart the other day, and found it illuminating: http://www.pbs.org/newshour/making-sense/hottest-chart-economics-means/ It shows the very rich in countries like the US are doing well, and rising economies like China are having growing middle-classes, but the middle-classes in countries like the US are disappearing with the quickness.
In terms of what holds the US together, I think in people's minds at least, the country is getting very, very divided, so it'll be interesting to see what happens.
There's been a lot of racism and inequality historically in the US for sure, but now that job losses and stagnating wages are really affecting certain segments of white America, we're seeing more and more these intense divisions. I also thought this interview was illuminating: https://www.washingtonpost.com/blogs/post-partisan/wp/2017/06/06/the-real-reason-working-class-whites-continue-to-support-trump/
Most Americans don't own stocks. Financial literacy is very low here.
True - like so many things in our society that can create wealth, the elite few have made it so technocratic, and subjected it to so much regulation, that the average man can't understand it.