If you press the button, the money in all white people's bank accounts in the US are cut in half, and the money in all US black people's accounts are doubled.
Would you press the button?
white people with no bank accounts lose nothing, and black people with no bank accounts gain nothing
Net debt is ignored; it's just, "what's the number in your bank account?"
Is this accomplished by magic? Or just moving of money? If the half subtracted from the white people's accounts is more than the amount added to black people's accounts, is that money simply destroyed?