The parallels between the child labor issue and the health care issue are remarkable. In both cases, the legislation in question was the product of a decades-long struggle. Universal health care has famously been a goal of American liberals since Theodore Roosevelt proposed it in 1912. The movement to abolish child labor, for its part, stretches back to the first years after the Civil War: When the Knights of Labor was founded in 1869, its constitution included a provision calling for abolition of child labor, and a similar position was adopted by the American Federation of Labor when it was created in 1886. The National Child Labor Committee was organized in 1904, and the first federal law was introduced in 1906. For his part, Roosevelt supported a national study of the problem.
Only the federal government could address the issue, since no state would act on its own. Even states that did not want child labor could not afford to get rid of it if their competitors still had it. Health care presents a similar problem: Any state that provides good medical care risks attracting sick people from other states. In both cases, unless Congress took action, the problem was going to stay unsolved. And so in 1916, Congress, using its power to regulate interstate commerce, banned the interstate shipment of the products of child labor. When it defended the law in Court, the government explained that this was an interstate problem: “The shipment of child-made goods outside of one State directly induces similar employment of children in competing states.”
Both then and now, challengers to the statutes had to propose that the Supreme Court invent new constitutional rules in order to strike them down. At the time it considered the issue in 1918, there was nothing in the Supreme Court’s case law that suggested any limit on Congress’s authority over what crossed state lines. On the contrary, the Court had upheld bans on interstate transportation of lottery tickets, contaminated food and drugs, prostitutes, and alcoholic beverages.
That’s why the Supreme Court’s invalidation of the law in 1918 astounded even those who had most strenuously opposed enactment. Hammer v. Dagenhart declared—in tones reminiscent of the Broccoli Objection to Obamacare—that if it upheld the law “all freedom of commerce will be at an end, and the power of the States over local matters may be eliminated, and, thus, our system of government be practically destroyed.” Justice Oliver Wendell Holmes, dissenting, wondered how it could make sense for congressional regulation to be “permissible as against strong drink but not as against the product of ruined lives.” The Court responded that unlike all the contraband that it had permitted Congress to block, the products of child labor “are of themselves harmless.” This meant a completely novel constitutional doctrine: The Court took unto itself the power to decide which harms Congress was permitted to consider when it regulated commerce.