In the 1930 case of McCaughn v. Hershey Chocolate Co., the Supreme Court ruled on a dispute involving taxation and import duties. The Hershey Chocolate Company had imported cacao beans from abroad, which were then processed into chocolate in their U.S factories. The company argued that they should not have to pay an import tax on these beans because they were being used for manufacturing purposes within the United States, rather than being sold as is. However, Collector of Internal Revenue McCaughn disagreed and imposed taxes on them under the Tariff Act of 1922. The Supreme Court sided with McCaughn, ruling that raw materials imported for use in manufacturing are still subject to import taxes even if those goods will be further processed after entry into the country. This decision upheld existing interpretations of tariff laws at that time and clarified how such laws apply to raw materials intended for domestic production processes.

In the dissenting opinion for McCaughn v. Hershey Chocolate Co., it was argued that the tax imposed on filled milk products should not be considered a penalty but rather a legitimate exercise of Congress's power to levy taxes. The dissenting justices believed that Congress had the authority to classify different types of dairy products and impose varying levels of taxation based on those classifications, as long as such distinctions were reasonable and not arbitrary or discriminatory. They contended that filled milk, which is made by replacing all or part of natural milk fat with vegetable oil while retaining other components like proteins and carbohydrates, could reasonably be classified differently from whole milk due to its distinct composition and nutritional value. Therefore, they thought it was within Congress's purview to impose higher taxes on filled milk if it deemed this necessary for public health or economic reasons. The dissenters also disagreed with the majority's view that taxing filled milk at a higher rate than whole milk amounted to prohibiting its manufacture altogether; instead, they saw this as merely discouraging its production in favor of more nutritious alternatives.