You can't have it both ways. Either you believe the Founding Fathers knew what they were doing (when they wrote a minimalist Constitution heavy on individual freedoms from government intrusion), or you believe in Congresses right to infinitely shade the penumbra of meaning anyway they like (effectively a dictatorship by a thousand slices), but you certainly can't believe the federal drug laws are legislatively legal AND Constitutional at the same time. Criminy, if Congress can do anything it believes is in the "general welfare", then we will soon be paying half our incomes in income taxes to support a welfare state! (oops, I guess that's where we are already).
Just please don't quote Congressional legislative self justifications as being the final word on what constitutes the "general welfare" or what is "Constitutional".
Sure you can. Your burden is to show that the Founders fought a Revolution to "throw off the shackles of England's prohibition on intoxicants".
"What is truth?" Isn't Pilate's evasive query the very archetype of a reality-denying lawyer's question?
They taxed whiskey, outlawed unlicensed production and sale, and put down the Whiskey Rebellion.
You just smoked your own position.