My short list of things which are NOT interstate commerce:
Growing your own wheat
Growing your own cannabis
Growing your own machine gun
Being Near a School With a Gun
Rape
Assisted Suicide
Partial Birth Abortion
Possession of kiddie porn
Certain California toads
The Supreme Court disagrees with me (well, except about the toads, I guess) but I'm undeterred. ;-)
I imagine the conversation between the feds and the State of Oregon...
Feds: You can use these drugs, but only for these purposes.
Oregon: We're going to let our doctors prescribe them to assist in planned suicides.
Feds: OK, well your doctors can tell patients how to kill themselves, but not with any drugs.
Oregon: Well approve these drugs for this use.
Feds: No, we can't approve those drugs for that use, it's not safe. It'll kill patients.
Oregon: OK. Give me the Agriculture Department.
Ag Dept: Hello?
Oregon: Got any of those things they use to brain cows?