The SC decision is still fresh on my mind. So I wanted to get this out there before I lost it. Justice Roberts says congress can tax people if they don't buy health insurance. I don't think he set out any limits in his decision or made the slippery slope argument that he did with congress' ability to enforce the mandate under the commerce clause. But there is a slippery slope argument to be made.
If congress can tax people for not buying insurance, what can't congress tax people for? We can even use the broccoli analogy here. If congress can tax people for not buying insurance, why can't congress tax people for not buying broccoli? Also, if congress can tax people X amount for not buying health insurance, why can't congress tax people an unlimited amount of money for not buying health insurance or broccoli, or tax them 99% of their income for an income tax?
I'm not sure if Roberts addressed these questions. And I'm not sure why they are any less important than the broccoli argument in relation to the commerce clause. I suspect Roberts would give the same answer Justice Ginsburg gave, which is basically that you don't have to explicitly spell out the limit of congress' power in this regard because there is sort of a natural limit. (Also notice that the constitution doesn't spell out the limits of congress' taxing power either)
Common sense and democratic accountability dictate that congress is very likely to not impose a 99% income tax rate or tax you X amount if you don't buy broccoli. Also, if you do impose a strict limit on what congress can do you risk handicapping it from solving problems, which is the reason it was given the power to tax and regulate commerce to begin with, and the reason the court expanded the previous limits the court had placed on the reach congress has with the commerce clause.
In short, it just doesn't follow that because congress is given a certain power that it will automatically want to extend that power to its most extreme end. Is there a danger of it happening? Sure. But it's not a certainty. If it was we couldn't give congress or the executive any power at all. There are limits. And the court has a role in deciding what those limits are. But it shouldn't try to define such limits based on shaky logic, which is what the slippery slope lined with broccoli argument amounts to.