Yeah I had a nice go-around at HA with some of the folks there about this very fact. Article 1 section 8 is often ignored by conservative minded folks.
It spells out that the Militia is controlled by Congress, and Second to state government, and Congress is in controll of " Organizing, arming and disciplining, the militia". No definition of militia as community organizing themselves, defending their little hamlets against big bad .gov tax collector types in this. Militias are created to "suppress Insurections and repel Invasions".
That throws a monkey wrench into the Second Amendment debates a bit, as the sentences above these statements refer to Navies and the "regulation of land and naval forces"
The " Power to lay and collect taxes" is well exercised, as is "To borrow Money on the credit of the United States"
But yeah, "establish post offices and post roads' was used to get the Eisenhower interstate system built.
And the" No Tax or Duty shall be laid on articles exported from any state" has gone to the wayside, but hey, it's their system, and I know better than to expect benefits or protection from "them".