[inquest]

can make the argument that Congress can get involved in ground transportation to the extent necessary to place obstructions thereto, and back it up with actual law.

You mean you can "back it up" with opinions from judges? Big deal. Back it up with the Constitution, or don't waste my time.

Correct. Unless they have a substantial effect on the interstate commerce that Congress is currently (and constitutionally) regulating.

So you claim. But the Constitution says nothing about substantial effects.

[robertpaulsen]

"But the Constitution says nothing about substantial effects."

Nor the right to privacy, nude dancing, sodomy, abortion, flag burning, "under God", "Miranda" rights, no-knock entry, asset forfeiture, an individual right to bear arms, libel/slander, and a whole slew of things.

So?