We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
If the Commerce Clause power had been upheld, not only would the enumerated powers scheme have gone away, but Congress could have changed the law to punish this or any future mandates by very extensive penalties, like high fines and even imprisonment. One last way of explaining the difference: Imagine that all the drug laws were justified under the tax power and not under the commerce power. All the drug laws we have are Commerce Clause power. But imagine they were only justified under the tax power, under the principle that Chief Justice Roberts identified. That would mean the only thing the government could do to you for violating the drug laws would be to charge you a reasonable, modest tax. They couldn’t even charge you a punitive tax, and they certainly couldn’t put you in jail. If we actually achieved that reading of the drug laws, it wouldn’t be a perfectly libertarian solution, but you’d have to open up the jails and let millions of people out under that reading of the Constitution.