At Balkinization, Gerard Magliocca raises a possible slippery slope argument against striking down the individual health insurance mandate (this argument was, I think, first raised in an article by Mark Hall):
The most powerful argument against upholding the constitutionality of the individual mandate may be that this will open the door to compulsory broccoli purchases. Many people are unfamiliar with the relevant Commerce Clause cases, but everyone seems to know about the broccoli hypothetical.
The hypothetical on the other side of this litigation, though, is just as powerful. Suppose that a dangerous epidemic breaks out that reduces interstate commerce by curtailing travel and other interactions for fear of contagion. A private company develops an effective vaccine that many people refuse to buy. Is Congress prohibited from ordering everyone in the country to buy the vaccine under the proposed activity/inactivity distinction?
It so happens that I address the very issue Gerard raises in a forthcoming article on slippery slopes and the individual mandate. I have two answers to his question. First, Congress can still pass a vaccination requirement that applies to everyone who crosses state lines. Crossing state lines is clearly an “activity” and an interstate activity to boot. Second, as a practical matter, state governments would have very strong political incentives to enact vaccination laws in the face of a “dangerous epidemic.”
Gerard anticipates my second point, and finds it unsatisfying because it “sounds a lot like ‘This is a non-issue because Congress will never order you to buy broccoli.’ Either both responses are valid or neither is. One can’t be adequate and the other not.” Not so. The claim that a slippery slope is politically infeasible may be right in one scenario and wrong in the other because some policies are more politically viable than others. As I explain in this post, Congress has strong incentives to enact purchase mandates that benefit influential interest groups. The insurance mandate was itself adopted in part because of backing by the health insurance industry. By contrast, state governments are unlikely to sit on their heels in the face of a raging epidemic. Any state that does so is likely to lose business, and its politicians are likely to suffer retribution at the polls. Even the most ignorant voters tend to notice a rampaging epidemic that the government has failed to control.
Obviously, state governments could do a poor job of addressing an epidemic even in spite of good incentives. But the same is true of Congress.
UPDATE: I have made a few, mostly stylistic, changes in this post.
UPDATE #2: It’s a fair point to suggest, as some commenters do, that under my logic, Congress could enact the individual insurance mandate by restricting it to people who cross state lines. I think that would be permissible under current Commerce Clause doctrine, even if it might not be under the text and original meaning. However, many people could still evade the mandate by avoiding interstate travel. Not everyone crosses state lines regularly. Moreover, a health insurance mandate tied to travel would seem weird to many people, which in turn would reduce its political feasibility (not so with a vaccination mandate tied to travel, since it’s easy to see that part of the purpose of such a mandate is to stop the spread of an epidemic across state lines). More generally, requiring mandates to be tied to “economic activity” of some sort reduces the risk of harmful mandates because mandates with “tie-ins” tend to disincentivize whatever activity they are tied to. The more onerous the mandate, the greater the disincentive. For example, a mandate tied to employment will tend to increase unemployment. Congress will not always be willing to pay that price.