Across the country, state legislators have introduced over 200 measures aiming to prevent the enforcement of federal laws and regulations they believe to be unconstitutional. Here in Texas, 25 such measures have been filed. But these efforts face long-ago-constructed hurdles, one of which is the law-school orthodoxy regarding the constitutional vision of the nation's greatest Supreme Court chief justice, John Marshall. Both defenders and critics of federal expansion tend to view him as a champion of Big Government. Against this tide stand two legal scholars, Robert Natelson and David Kopel, who argue that both sides get Marshall wrong, and that we must get him right to reeducate ourselves in the constitutional basis for individual liberty and limited government.

In a thought-provoking exercise, Natelson and Kopel delve into the seminal opinions currently seen as proof of his judicial activism. They construct what a Marshall opinion on Obamacare would look like, drawing "chiefly from direct quotation and paraphrases of Marshall's own words." They ask, "Would the nationalist justice who, according to the New Deal Supreme Court, 'described the Federal commerce power with a breadth never yet exceeded,' agree that federal control of health care was within that power?"

Their answer is a resounding no. They find Marshall "far more restrained ... than the caricature drawn by case book editors and law professors," whose abridged accounts of Marshall's opinions "depict him as an activist in the cause of federal power."

Obamacare's defenders offer three arguments for the law's constitutionality. First, they point to Congress's power to "provide for ... the general Welfare." In weighing this claim, Natelson and Kopel's constructed "Marshall opinion" begins with his statement in McCulloch v. Maryland that the touchstone for proper interpretation is the "contemporaneous exposition" of those who ratified the Constitution. When it came to the General Welfare Clause, contemporaneous accounts, by both opponents and defenders of the proposed Constitution, asked whether it would lead to the virtually unlimited power this clause today is read to provide. Defenders allayed these fears by stipulating that the clause was not a "grant of power" but, instead, "served merely as a limit on the taxing power." In fact, the expansive interpretation underpinning Obamacare was advanced by Justice Story in Brown v. United States (1814). It was rejected by every other justice on the Supreme Court. In sum, Marshall's reading of the General Welfare Clause provides no basis for the constitutionality of Obamacare.

The second argument in the defense of Obamacare is Congress's constitutional power to "regulate Commerce ... among the several States." Here again, both Obamacare's defenders and critics read Marshall wrongly, asserting that, under Marshall's ruling in Gibbons v. Ogden, the federal power can legitimately reach to any economic activity deemed to "substantially affect" interstate commerce. Both focus on Marshall's statement in Gibbons that "commerce undoubtedly is traffic, but it is something more: it is intercourse." Employing Gibbons, the Court has over the last century validated congressional action in a number of areas previously regarded as the province of the states.

But while Marshall's Gibbons opinion finds the Commerce Clause includes the power to regulate navigation, this very opinion also lists powers reserved to the states alone, among which are "health laws of every description." This portion of his opinion is ignored by those who deem him a defender of expansive federal government.

The third plank in the Obamacare defense holds that the law is "necessary and proper for carrying into Execution" the federal government's interstate-commerce power. Marshall's written opinions deny such an expansive interpretation of the Necessary and Proper Clause. To be sure, he grants in McCulloch that there is no provision in the Constitution that "excludes incidental or implied powers; and which requires that everything granted shall be expressly and minutely described." He adds in Cohens v. Virginia (1821) that any power granted under the Constitution "carries with it all those incidental powers which are necessary to its complete and effectual execution." But his very defense of incidental powers defines them as necessarily less important than the principal powers they serve. Health care constitutes one-sixth of the economy; as such, it cannot be a mere "incident" of interstate commerce.

Nevertheless, the Obama administration offered this clause to the Court in defending the requirement that individuals purchase health insurance, arguing that such purchases "affect" interstate commerce. In rejecting this interpretation, Natelson and Kopel's construction of Marshall's opinion relies on "the intention of the makers, that is to say, the ratifiers of the Constitution."

Here Natelson and Kopel look to Marshall's anonymous newspaper essays published in defense of McCulloch. They find that scholars generally miss the meaning of key terms employed by Marshall. For example, in defending the constitutionality of "incidental powers," Marshall stipulated in an essay that these must be "the natural, direct, and appropriate means, or the known and usual means, for the execution of the given power." This might seem to contradict the text of McCulloch itself, which said that "incidental" frequently means "no more than that one thing is convenient, or useful, or essential to another." But "convenient" did not for Marshall have the expansive meaning some give it now. Johnson's contemporaneous Dictionary of the English Language (Marshall's favorite dictionary) defines "convenient" as "fit; suitable; proper; well-adapted." Sheridan's 1789 Dictionary concurs. Nor did the term, "appropriate," when defining incidental powers, carry the wide meaning attributed to it presently. Bacon's 1786 Abridgment of the Law (cited in 55 Supreme Court cases, most recently in 2001) declares "the incident must be one without which the principal would labor under 'great prejudice.'"

On this basis, McCulloch held incorporation of a national bank constitutional as an "incidental power" to Congress's enumerated powers. Incorporation was deemed "not of higher dignity" but, instead, "of inferior importance" to the enumerated powers. Therefore, while Obamacare's defenders correctly assert that its required purchase of health insurance "affects" interstate commerce, so also do many other activities. Yet the clear intent of those who ratified the Constitution was that -- as Marshall himself testified at the Virginia Ratifying Convention -- any law "affecting contracts, or claims, between citizens of the same state would go beyond the delegated powers and would be considered by the judges as an infringement of the Constitution." Thus, the claim that Obamacare is "incidental" to Congress's enumerated powers falls. Obamacare's provisions are "at least as substantive and independent" as the regulations governing interstate commerce; they are not merely "incidental" to them.

Finally, McCulloch holds that, for a power to be truly incidental to Congress's enumerated powers, "the end must be legitimate," meaning, "within the scope of the Constitution." But Obamacare's self-confessed purpose is to "protect patients" through regulating health care and health insurance. "That the Act was designed truly to regulate commerce is mere pretext," the authors write, as is the administration's contention that "penalties imposed on those who do not purchase insurance are taxes rather than penalties. ... Those exactions are penalties alone."

Will Natelson and Kopel's carefully reasoned arguments reach the law schools, sparking much-needed debate? No one knows. But as state legislators continue their long march against federal overreach, they should be encouraged to know that, in their battle to restore limited government and individual liberty, America's greatest chief justice is not, as they thought, an enemy, but a true friend.

Thomas K. Lindsay directs the Centers for Tenth Amendment Action and Higher Education at the Texas Public Policy Foundation and is editor of SeeThruEdu.com. He was deputy chairman of the National Endowment for the Humanities under George W. Bush.