You think people ship chemical weapons into this nation are engaging in commerce?
Perhaps you don't remember this, but a few years ago, Brian Williams (currently of ABC News) once shipped Uranium into the country to demonstrate how easy it was for terrorists to do it.
Do you think he was engaging in "Commerce"?
Do you think people sending Anthrax through the mail are engaging in Commerce?
I dare say "commerce" does not extend to the illegal shipment of dangerous/deadly substances across our borders. Such things are attacks on our people and our sovereignty.
Those who ship mind-altering drugs make money from it - money voluntarily paid by those to whom it is shipped. How is that not commerce?
Here's the deal with "original intent" - It doesn't matter what your or I think. Asking what I think about it is just a distraction to keep you from having to actually provide any answers.
What matters is what the people who wrote and ratified the Constitution thought.