If the interstate commerce clause doesn't apply, then you need to provide a Constitutional justification for Federal intervention.
I did not say the commerce clause did not apply, I'm saying that the wooden-headed bastards in telemarketing don't understand that people who say they don't want to be called actually mean THEY DON'T WANT TO BE CALLED.
Y'all are attempting to engage in interstate commerce, and are subject to Federal regulation, no matter how unlikely/impossible actually engaging in interstate commerce during a crank call might be.
My problem is why you can't understand that if 50 million people say 'Don't bother calling, I will not buy,' you still insist on the 'right' to make the call.