As a minor follow-up to Ilya’s post below on the lack of consensus among constitutional scholars about the constitutionality of the individual mandate, I would ask a question: Is there a consensus among constitutional scholars about the constitutionality of anything? The only thing I can think of is Brown v. Board. Everyone agrees school segregation is unconstitutional. Beyond that, the consensus seems to break down: No two constitutional scholars have the same theory of what the Constitution allows, and you can pretty much always find someone to say a controversial law is unconstitutional.
As for the constitutionality of the individual mandate, my sense is that if we’re more precise we end up with conclusions something like this: (a) it’s constitutional if you follow existing judicial precedents, (b) it may or may not be constitutional if you follow a particular theory of constitutional interpretation, depending on which theory you follow, and (c) legislators and the President should exercise their own independent responsibility to ensure that the legislation is constitutional, a responsibility that they can plausibly satisfy by following either judicial precedents or some normative theory of interpretation. That’s my sense of things, at least.