The middle class in america is shrinking because of inequal wealth redistribution. Super riches amass more and more wealth through their stored wealth, while the revenues of the middle class lose its purchasing power because of that "controlled" inflation which never allow salaries to rise despise the rise of price of goods, or if you prefer, the cost of living.

What created the middle class in America and western world was created thanks to redistribution of wealth through a tax sheme taxing you more according to your wealth, and these taxe paying for public expense, like medical care, instruction, public infrastructure and so on.

Neo-liberal policies and tax reform removed that burden from the wealthiest and cut "public funding" shifting the cost of services assumed once by a strong State to individuals, like instruction.

That's how wealthiest are now allowed to accumulate more and more wealth, and middle class is burdened under a crippling amount of debt.

15 years ago, Bill Gates wealth was "only" 50 billions. Now it's 100. And in 20 years it will be 200. On the other end, diabetics are dying because they have to save on insuline shots, people affected by cancer has to fill for bankrupties because of the cost of their treatment, people avoid visiting the doctor for serious issues unless it's a matter of life or death. Cuba has a better life expectancy rate than the Us.