I will open by saying that the US party two party system is the root of a fair amount of issues in US. Normally, I would argue for some sort of rebalancing to ensure that the system works, but the power centers are too firmly entrenched and any real change would require major political capital. After all, levers are known. Who knows what kind of levers new system would introduce. In that sense, the party system is too far gone.
And it is a feature Trump successfully exploited. It is interesting to note that Sanders and Bloomberg are also exploiting that system; just in different fashions. And I am perfectly OK with both of their approaches though I favor Sander's as it seems more honest.
All that said, with your point about being better off under Democratic reign of terror versus Republican reign of terror, I just gave you an entire list of grievances of the forgotten class ( as the current president sometimes dubs them ). Those grievances did not get addressed by either party over the last 40 years. Worse, Clinton signature is on NAFTA papers.
I would agree with you on Trump vs Sanders as they, amusingly, shared a lot of the populist message. I have my pet theories, but they would just derail this thread altogether.
I would like to note that it is hard for me to argue that Trump policies ( with exception of Soybeans and the bailout there ) has not done anything for them. For better or for worse, Trump is very keen on listening to his core supporters. He seems to genuinely care about his ratings, which does lead to all sorts of theatrics ( as you note ).
That said, note that regardless of how it was achieved and how we are going to pay for it in the future, unemployment now is low and entry level wages are up. Just that fact alone should give you pause, because that likely means that some do feel relief under Trump.
You have to admit that from that perspective a voter may be inclined to vote for Trump again in 2020.