How about:
Amendment XVI.
The Congress shall have power to lay and collect taxes on incomes, from whatever source derived, without apportionment among the several States, and without regard to any census or enumeration.
How's that?
Weak.
Define income. And show me where it repeals the clause that says that direct taxes must be apportioned. Income taxes were already defined as "indirect."...Therefore the 16th changed nothing.
Better luck next time.