I think you are on the right track when you compare the Brexit surprise to the Trump phenomenon. There are many of us who view the main difference between the Democratic and Republican establishment as only the particular special interest, large donors they serve. George Bush was many things, but a fiscal conservative is NOT one. He was the one who pushed through Medicare Part D which contributed greatly to our unfunded liabilities. Every president since Johnson has raided the Social Security Trust Fund to help hide our debt. President Obama has presided over the doubling of our national debt, to over $20T. He had a lot of help from both sides of the aisle.
Many of us here realize that this exponential growth in national debt supported by printing unbacked fiat currency cannot continue. We will be in especially deep trouble if other nations decide not continue to use the US dollar as the reserve currency. We cannot continue to outspend on defense the next 11 or 12 nations combined. We cannot solve every crisis in the world.
We do not have a perfect choice for president. We never do. We do know that Mrs. Clinton is another one who sees more government intervention as the solution to every problem. She was not very effective as Secretary of State and I am surprised she has not been indicted for compromising national security with her private email server. Even if they had put up Sen. Sanders, his own wife's experience (shutting down the college she presided over because it was economically unsustainable, getting a nice severance package, leaving the students with debt...) shows that his plan is unworkable. At least Mr. Trump realizes that not every expenditure is possible or prudent. He seems to understand the concept of 'vital national interests' - that we must get our own house in order before we can continue to help the greater global community.
Those of us who say this are often publicly vilified. We do not seem to be able to have a peaceful, rational exchange of ideas. So people will keep their mouth shut and go cast their ballot in the privacy of the voting booth, exercising their fundamental human right guaranteed by under a constitutional republic. Gee, it sounds a lot like what the voters in the UK just did.