Sorry, wrong burden of proof. In a limited government with enumerated powers, you have to be the one to show that a law or agency is constitutional, because it is specifically authorized in the Constitution. Where's the Constitutional authorization for the DEA? Where's the Constitutional authorization to prohibit leafy substances? If it isn't explicitly spelled out, it's unconstitutional.
Roscoe, has a problem. He seems to think that if Congress passes a Law, that it is therefore "Constitutional" and that circuit court judges are never wrong (unless they have ruled contrary to whatever point Roscoe happens to be trying to make).
He's also got some problems with the way the Constitution is applied to the States.
Treat him like you would a broken record of a tune you have long gotten tired of listening to.