1. Whatever happened to increasing tax rates, like pretty much every other country? Why these weird gimmicks?
2. A much greater cause of elite wealth accumulation is running deficits. Deficits are when you want to spend on social welfare but don't have the courage to pay for it with taxes. So you make both sides happy and increase spending while running up deficits. The reason we've seen this astronomical increase in top incomes is because of massive deficit spending.
3. Any tax bill targeting billionaires is going to fail since they can give up US citizenship and offshore whatever they want. If you are serious about soaking the rich, you need controls on capital flight. But that goes against the neoliberal project of globalization. Commitment to that project is going to make any soak-the-rich effort not work. It will end up hitting the upper middle class that can't offshore -- they are the real targets.
4. Envy-based politics don't work. There is a dangerous game being played here. You want to inculcate solidarity and national purpose, but again that goes against the liberal project that only tells us who we are supposed to hate based on their race and/or class.
5. If you have a low interest rate policy, then you are going to make a lot of billionaires much richer via capital appreciation. That's not the fault of the billionaires. If you want to reduce that, then raise interest rates. All these billionaires will become much poorer. Because this is all just paper wealth.
6. The Original Sin of the left is trying to mess with prices instead of incomes. Tax incomes, not repricing of wealth.