I'll go with the Supreme Court's rulings in Lopez and Morrison. The Commerce Clause applies to anything that crosses the border of a State, into the United States, from an Indian reservation, is using a pathway for interstate commerce (an intrastate flight would apply here), or "substantially affects" interstate commerce.
How does smoking, or otherwise using, marijuana that's been grown and used in the same State "substantially affect" interstate commerce?
Scalia: "As the court explains, marijuana that is grown at home and possessed for personal use is never more than an instant from the interstate market -- and this is so whether or not the possession is for medicinal use or lawful use under the laws of a particular state. Congress need not accept on faith that state law will be effective in maintaining a strict division between a lawful market for 'medical' marijuana and the more general marijuana market."
Don’t play his flying airplanes game. He has been soundly trounced on that false example countless times.
You don't have to. You can go with their their decision in Gonzales v Raich, a case specifically about medical marijuana.
I see that Mojave already quoted Justice Scalia from that case, so there's no need for me to repeat it.