“First, we already have a tax on wealth;”
There is a federal inheritance tax on amounts above $11.4 million, but revenue from it is less than $20 billion per year (less than 1% of total federal tax revenue. Most of the super rich, to whose estates the tax would apply in principle, are able to shelter much of their assets from this tax.
I’m not defending a wealth tax; on the contrary, I think it would raise little revenue, and further distort individual saving and investment decisions.