How Do We Know What is An “Activity” for Commerce Clause Purposes?

I appreciate Ilya’s post below on the meaning of “activity” in Commerce Clause jurisprudence, and I wanted to add two brief observations:

1) If I understand Ilya’s argument, he begins with an assumption as to how much power Congress has, and he then reasons backwards to infer the meaning of “activity” in order to make that assumption correct. A conscious decision not to do something cannot be an “activity,” the thinking goes, because that would give Congress more power than a fair reading of the Commerce Clause would permit. Perhaps, but it seems to me that this argument largely assumes its conclusion. It uses the fact that Congress must have significant limits on its power to show that “activity” has a narrow meaning, which then is used to prove that Congress has significant limits on its power that the individual mandate exceeds. If you start with a different assumption, however, the argument doesn’t work. For example, if you start with the assumption about the scope of the Commerce Clause that Justice Kennedy articulates in his Lopez concurrence, then you can get a different meaning of “activity.”

I suspect some readers will object to this argument on the ground that they share Ilya’s assumption: Because Ilya’s assumption is correct, the argument works. That’s a fair point within the group that shares the assumption. The problem is that others don’t share the assumption, and starting with it won’t go very far in persuading them. That doesn’t necessarily mean Ilya is right or wrong. But I do think it means that this argument is likely not have a lot of force among the people not already inclined to agree with it.

2) More broadly, I still think that the easiest path to resolving the constitutionality of the individual mandate is that it is a “necessary and proper” means of trying to regulate the massive interstate market in health care that is around 1/7th of the United States economy. As I have blogged before, I think that’s a very strong argument based on Supreme Court caselaw on the meaning of “necessary and proper.” I realize that Ilya thinks that the Supreme Court precedents on the meaning of “necessary and proper” have not actually addressed what is “proper,” and thus that there is a still yet unarticulated limitation on the scope of federal power that remains to be developed — and that should be read as adding a level of scrutiny that the individual mandate fails to satisfy. But I don’t think the cases can be fairly read in that way, so it seems to me that the necessary and proper clause caselaw leads to the conclusion that the mandate should be upheld without getting into what counts as an “activity.”