Since America was the wealthiest country in the world, it looked obvious that with globalization bringing some readjustment of inequality America would be the biggest loser. That's a simple situation i felt decades ago. i think it still holds.
In the past few years i've come to the conclusion your political system has real problems. That's now obvious, as the whole world has seen .
The idea of American exceptionalism has sucked many in, and as you say expectations have been too high for too long for some.