I personally don't care whether someone in California takes pot, and it runs contrary to spirit of liberty which used to animate this country for anyone else to care about it.
As for the current Supreme Court case, if the court holds for the government, it will come close to a reversal of Lopez and Morrison. If growing and consuming your own pot in your own garden falls under the power of the Commerce Clause, then there are almost no limits to federal Congressional power.
There is no limit...just ask them. :-)
The government's lawywers are arguing that there cannot be an "as applied challenge" to Commerce Clause legislation. IOW - they're arguing that there is no such thing as a misapplication of the Commerce Clause. If that argument prevails, it will not "come close" to a reversal of Lopez and Morrison, it will dictate it.