To say the least. The statement in the Cons ution,
"The Congress shall have Power To lay and collect Taxes,"
has been seen from the beginning as empowering any sort of tax that a government might impose. It was intended that way. The Founders didn't presume to know exactly what sort of taxation would be needed to support the new government they were creating. They left the specifics to later generations, based on experience.
The power of the USA to collect an income tax was always there. The Pollock case, and then the 16th amendment, only addressed details of exactly how the congress had to go about it.
But on the more important matter, Tim Duncan's hair, the younger generation might prefer his casual look, and their votes are important. Getting an "establishment" haircut could cost him votes.