WASHINGTON – Although Democrats think their health care legislation faces smooth sailing to implementation, there is a rock dead ahead – a constitutional challenge to the legislation’s core. Democrats who assume it is constitutional to make it mandatory for Americans to purchase health insurance should answer some questions:

Would it be constitutional for the government to legislate compulsory calisthenics for all Americans? If not, why not? If it would be, in what sense does the nation still have constitutional, meaning limited, government?

Supporters of the mandate say Congress can impose it under the enumerated power to regulate interstate commerce. Since the New Deal, courts have made this power capacious enough to include regulating intrastate activity that “substantially affects” interstate commerce. Hence Congress could constitutionally ban racial discrimination in “public accommodations” – restaurants, motels, etc. – as an impediment to interstate commercial activity.

Opponents of the mandate say: Unless the Commerce Clause is infinitely elastic – in which case, Congress can do anything – it does not authorize Congress to forbid the inactivity of not making a commercial transaction, of not purchasing a product (health insurance) from a private provider.

“Congress can regulate commercial activities in which people choose to engage, but cannot require that they engage in those commercial activities.” So says Sen. Orrin Hatch, who also notes that if Congress can mandate particular purchases in order to help the economy, there was no need for Cash for Clunkers: Congress could have ordered people to buy cars (with subsidies, if necessary). Why not the Anti-Couch Potato Act To Make Calisthenics Mandatory and To Impose a $50 Excise Tax on Cheeseburgers Because Unhealthy Lifestyles Affect Interstate Commerce?

Many liberals, says Hatch, spent eight years insisting that “the Constitution sets definite and objective limits that the president must obey.” There are, however, no constitutional controls on Congress if there are no limits on its power to declare all its preferences “necessary and proper” for the regulation of commerce.

Stuart Taylor, a judicious analyst of legal matters, says (in National Journal) that the Supreme Court probably would uphold the constitutionality of the mandate, for two reasons: Because uninsured people create substantial economic effects by seeking free care from emergency rooms. And because the mandate is, in Congress’ judgment, “necessary and proper” for financing health care reform.

But if any activity, or inactivity, can be declared to have economic consequences, then anything can be regulated – or required. Furthermore, judicial review, and the Constitution itself, is largely nullified by a doctrine of virtually unlimited judicial deference to Congress’ estimates of what is “necessary and proper” for the regulation of commerce.

If Congress does something beyond its constitutional powers, that something does not become constitutional merely by Congress saying it is necessary for this or that.

Taylor also says that the alternative to upholding the mandate is for the court to strike down a president’s “signature initiative – something that no court has done in 70 years, for good reason.” The reason is a general duty to respect government decisions arrived at democratically. Which brings us to what conservatives must believe in order to believe that the Supreme Court should declare the insurance mandate unconstitutional.

Judicial review – let us be candid: judicial supervision of democracy – troubles people who believe, mistakenly, that the Constitution’s primary purpose is simply to provide the institutional architecture for democracy. Such people believe that having government by popular sovereignty is generally much more important than what government does; hence courts should be broadly deferential to preferences expressed democratically. This is the doctrine of those conservatives who deplore, often with more vigor than precision, “judicial activism.”

More truly conservative conservatives take their bearings from the proposition that government’s primary purpose is not to organize the fulfillment of majority preferences but to protect pre-existing rights of the individual – basically, liberty. These conservatives favor judicial activism understood as unflinching performance of the courts’ role in that protection.

That role includes disapproving congressional encroachments on liberty that are not exercises of enumerated powers. This obligatory engagement with the Constitution’s text and logic supersedes any obligation to be deferential toward the actions of government merely because they reflect popular sovereignty.

The latter kind of conservatives are more truly conservative than the former kind because they have stronger principles for resisting the conscription of individuals, at a cost of diminished liberty, into government’s collective projects. So a constitutional challenge to the mandate serves two purposes: It defies a pernicious idea and clarifies conservatism.

© 2010, Washington Post Writers Group