In 1919, back when the United States was a constitutional republic, Congress passed a child labor law imposing a 10 percent excise tax on companies that violated it. A North Carolina furniture maker challenged the law and won. In 1922, the Supreme Court ruled in Bailey v. Drexel Furniture that although child labor laws have a noble purpose, the means – Congress using taxing power as a penalty – was unconstitutional. This was before Franklin Roosevelt’s court-packing threat in1937 ended the Supreme Court’s resistance to grandiose expansions of federal power. The child labor issue, by the way, was resolved when...