The framers of the 16th Amendment thought about scrapping the direct tax clauses entirely, but they decided instead to limit the amendment to “incomes.” An income tax is a tax on wages and money received from property, while a wealth tax is a tax on the value of property itself. The amendment applies to taxes on income, not to taxes on wealth.
Wealth tax proponents might argue that progressives ought not trim their sails simply because they fear that hostile justices will strike down their policies. Certainly, it would have been bad advice to tell President Franklin Roosevelt not to pursue the New Deal because a conservative court would fight back. But this is not an instance of ideologically motivated jurists pulling a rabbit out of a hat. A good-faith reading of history and precedent would suggest that the Warren and Sanders wealth taxes are unconstitutional.
I forget — what is it Senator Warren teaches at Harvard?
If the obstacle is a “good faith” reading of the Constitution, then Warren is unlikely to be hindered. Good faith is not her business.