From time to time I punch holes in โprogressiveโ myths about the Constitution and the American Founding. But conservatives and libertarians have their own myths as well.
One is that congressional authority under the Commerce Clause (I-8-3) to โregulate Commerce among the several Statesโ permits Congress only toย facilitateย trade among the Statesโi.e., that โto regulateโ means only โto make regular.โ The claim is that the Commerce Clause does not empower Congress to burden or obstruct commerceโand therefore Congress has no power to ban trade in products such as obscenity, marijuana, or goods made with child labor.
This argument, like so many other constitutional claims, seems to have arisen among partisans in the 19th century, but it remains popular among some libertarians today. Its promoters observe that a major reason for the Interstate Commerce Clause was to enable Congress to smooth out barriers to trade that some states had erected against other states.
Unfortunately for us free traders, the argument is false. Congressโs power to โregulate Commerce . . . among the several Statesโ is far wider than merely authority to make trade regular. Congress also may obstruct trade, or even ban it.
Whereโs the proof?
Well, first, letโs examine Founding-Era English dictionaries. To my knowledge, not one limits its definition of โregulateโ to โmake regular.โ In fact, of the 18 Founding-Era legal and lay dictionaries Iโve examined (counting multiple editions of the same publication as a single dictionary), NONE even includes the definition โmake regular.โย Instead, definitions of โto regulateโ generally include phrases such as โto direct,โ โto adjust,โ โto govern,โ and โto determine or decide.โ
Second, when you interpret a phrase in the Constitution, you have to consider not only its immediate purpose, but how people generally understood it. The phraseโregulate Commerceโ is a good example. All throughout the Founding Era, Americans used those words mostly to refer to governmentย restrictionsย on commerce, such as trade bans, price regulation, and prohibitory tariffs. For example, before the Revolution American colonial writers resisting Parliamentโs efforts to tax them nevertheless accepted British restrictions on trade as legitimate efforts to โregulateโ the trade of the empire.
Third, in the Commerce Clause the verb โregulateโ has three objects, not just one: interstate, foreign, and Indian commerce. Under Founding-Era (as well as modern) rules of interpretation you should read โregulateโ the same way for all three.
But a major reason for giving Congress authority to regulate foreign commerce was to enable Congress toย keep outย foreign goods. The idea was to encourage American manufactures and rectify an unfavorable balance of trade. And a major reason for giving Congress power to regulate the Indian trade was allow Congress toย block or limitย sale of certain goods to the Natives, specifically liquor and firearms.
So even though the Founders thought that an immediate use of the Commerce Clause would be to free up interstate trade, the Founders also gave Congress authority to obstruct it. This authority included power to burden or ban trade in selected items or from selected sources. And Congress could use that power for any reason not otherwise prohibited by the Constitution. Hence, even though the Constitution left direct governance over subjects like obscenity and marijuana to the states, the document gave Congress authorityย indirectย power to affect such items by preventing them from crossing jurisdictional lines.
โProgressivesโ and their allies on the Supreme Court have interpreted congressional authority far too broadly. But this does not justify the rest of us committing the opposite error.
- How the Founders Explained Limits on the Federal Government - January 21, 2026
- The Constitution and the Trump Tariffs - December 7, 2025
- Ancient Rome and the Constitution - October 29, 2025
