“Where necessary to make a regulation of interstate commerce effective, Congress may regulate even those intrastate activities that do not themselves substantially affect interstate commerce.”
Justice Scalia doesn’t make sense here. If the intrastate activity doesn’t affect interstate commerce, then why should Congress regulate it?
And I guess this is one of those penumbra thingies. “[The Congress shall have power] To regulate Commerce with foreign Nations, and among the several States, and with the Indian tribes”. This does not say Congress shall have power to regulate other things.
Notice the word "substantial". It's because they're out to stop activity X, regardless of jurisdiction.
Raich ruled that ANY activity REDUCING demand in ILLEGAL interstate commerce could be regulated (and that justified a "dynamic raid" on a terminally ill elderly lady growing 6 pot plants under her doctor's care in accordance with CA state law).