Income distribution and the middle-class

It is almost impossible to find empirical evidence that punishing the top earning income class is a failed policy.

But empirical evidence exists. Cuba.

The entire top class of entrepreneurs, probably no more than 10,000, were driven out of Cuba in the early 1960s.  Cuba had a fairly healthy middle class at the time.  The next forty years saw the middle-class fall into poverty along with the entire population of Cuba.  Cuba became and has remained a third world country.  I've been there. Havana has little or no decent food and except for tourist related buildings, the city and its infra-structure is in total disrepair, just like Budapest was when I saw it in 1991.

That is what happens when you punish the top economic class.  You probably don't have to drive them out, you just have to punish them with high taxes.