From the 1930s to the Reagan Revolution, America grew the largest and most robust middle class in history. Along with strong unions, the main driver of that was that people earning more than about $10 million in today's money confronted a top tax rate of 91% until the 60s, and 67% until Reagan came into office. That top tax rate encouraged CEOs and other wealthy people to re-invest their money in expanding their businesses and paying their employees well, rather than simply sticking it in offshore bank accounts.

Bernie Sanders and Elizabeth Warren are both proposing a return to top tax rates over 50%, like most other developed countries still have, and if they're successful it will bring back the middle class and cause businesses to start investing in their people again.

-Thom