The Washington Post hosts an op-ed (on Saturday, of course -- the lowest circulation day of the week) questioning the constitutionality of ObamaCare. Written by David B. Rivkin Jr. and Lee A. Casey, the article demonstrates that a health insurance mandate is unconstitutional:

The Constitution assigns only limited, enumerated powers to Congress and none, including the power to regulate interstate commerce or to impose taxes, would support a federal mandate requiring anyone who is otherwise without health insurance to buy it. ....

The otherwise uninsured would be required to buy coverage, not because they were even tangentially engaged in the "production, distribution or consumption of commodities," but for no other reason than that people without health insurance exist. The federal government does not have the power to regulate Americans simply because they are there. Significantly, in two key cases, United States v. Lopez (1995) and United States v. Morrison (2000), the Supreme Court specifically rejected the proposition that the commerce clause allowed Congress to regulate noneconomic activities merely because, through a chain of causal effects, they might have an economic impact. These decisions reflect judicial recognition that the commerce clause is not infinitely elastic and that, by enumerating its powers, the framers denied Congress the type of general police power that is freely exercised by the states.

This leaves mandate supporters with few palatable options. Congress could attempt to condition some federal benefit on the acquisition of insurance. States, for example, usually condition issuance of a car registration on proof of automobile insurance, or on a sizable payment into an uninsured motorist fund. Even this, however, cannot achieve universal health coverage. No federal program or entitlement applies to the entire population, and it is difficult to conceive of a "benefit" that some part of the population would not choose to eschew.